Actors Ellen Pompeo, Sandra Oh, Katherine Heigl, Justin Chambers and T. R. Knight reprised their roles as surgical interns Meredith Grey, Cristina Yang, Izzie Stevens, Alex Karev and George O'Malley, respectively, continuing their expansive storylines as focal points throughout the season.

The season followed the continuation of the surgical residency of 5 young interns, as they experience the demands of the competitive field of medicine, which becomes defining in their personal evolution.

The season also aired a 2-part episode arc, which primarily served as a backdoor pilot for a proposed spin-off, Private Practice, focusing on the departure of Walsh's character, Dr. Addison Montgomery.

Despite the negative critical response, the performance of the cast members and the production technique of the crew received outstanding recognition through numerous awards and nominations.

Other prominent directors were Jeff Melman, Michael Grossman, Julie Anne Robinson and Adam Arkin, each directing 2 or more episodes during the season.

Danny Lux continued his position as the main music composer for the series, while Herbert Davis and Walt Fraser served as the season's cinematography directors.

Susan Vaill and Edward Ornelas resumed their positions as editors, seeing David Greenspan, Matthew Ramsey and Avi Fisher being added to the team.

[32] Before the production of the season officially began, producer Shonda Rhimes stated that she was planning a major development in Ellen Pompeo's character, Meredith Grey.

Executive producer Betsy Beers stated that the writing staff was going to focus on the balance between her vulnerability and her courage, also dealing with changes in the relationship with her friends.

Cast member Eric Dane described the impact his first scene in the season had on him, stating that it was a spectacular entrance: "It was a brand new towel, which had a hard time staying together.

Rhimes also described the difficulty she faced in finding an appropriate love-interest for the character of Alex Karev: "We kept meeting with people and it wasn't until we met Elizabeth Reaser and sat down with her, and 2 seconds into it we realized that she was absolutely the one we'd been looking for.

Executive producer Rob Corn stated that his plan for the original arc was about Jane Doe's inner life, struggling to get out of the situation she is trapped in.

"[29] Betsy Beers, the show's supervising executive producer, found Izzie to have been marked for life by Denny's death, which matured her "in a very sobering way", but played a major role in making her feel more confident.

[39] Subsequent reports confirmed the decision, stating that an expanded 2-hour broadcast of Grey's Anatomy would serve as a backdoor pilot for the proposed spin-off.

[41] The backdoor pilot that aired on May 3, 2007, sees Addison take "a leave-of-absence" from Seattle Grace Hospital, to visit her best-friend from Los Angeles, Naomi Bennett, a reproductive endocrinology and infertility specialist, in order to get pregnant.

[42] The cast included Amy Brenneman, Paul Adelstein, Tim Daly, Taye Diggs, Chris Lowell and Merrin Dungey.

[45] The premiere episode followed the second part of the season debut of Dancing with the Stars, and provided a lead-in to fellow freshman series, Dirty Sexy Money.

Following a positive outlook on the second season, Christopher Monfette of IGN Entertainment expressed disappointment during the third one, mainly due to the declining quality and lack of realism of the storylines.

"[56] Whereas Monfette acknowledged that the fans would consider the problem to have been a simple case of lazy writing, he noted that over-writing played a main role in the series becoming unexpectedly unrealistic.

Monfette once again noted the lack of realism in the improvement of Jane Doe's condition, as she gives birth to her baby and undergoes reconstructive surgery in a short amount of time.

However, her incapability and continuous struggle to remember who she is, was considered to be "the most affecting and honest plotline of the season", noting the nuanced and emotionally resonant scenes, which gave the show a "charmingly positive, feel-good foundation."

Monfette considered Izzie's affair with George as the season's worst but most significant storyline, criticizing it as being "force-fed, emotionally-incorrect, a mismatch from the beginning and a narrative long-shot", which does not express love, but lust.

He agreed that the essential problem of the season was its reluctance to move, leading to frustration after seeing "the entertaining familiar characters so weighed down by their most annoying of traits.

"[56] In response to the season premiere, Oscar Dahl of Buddytv.com noted the predictability of the series, but expressed hope in its further development, by stating that it has become "a medical chick flick, but a damn good one" with a big and attractive cast.

However, Dahl expressed disappointment in the over-emotional scenes, describing them as "off-putting" and "not believable", while comparing them to real-life interactions between people who emote in a more subtle manner than displayed on television.

Rorke named her the show's heroine, and wrote that "Izzie is a welcome, calming presence, despite the devastation she experienced when she failed to save her patient and fiancé Denny Duquette", considering her to have been more prominent than the title character, Meredith Grey, whose storyline received negative critiques: "She used to be the queen of the romantic dilemmas.

Prior to the 59th Primetime Emmy Awards, Stuart Levine of Variety reviewed the performances of the 3 cast members nominated in the Outstanding Supporting Actress category.

[66] The title of the box set, "Grey's Anatomy: Season Three – Seriously Extended" is a pun, referring to the success the series had, using the medical term "extension."

"[69] Omnipresent in the bonus material were executive producers Shonda Rhimes and Betsy Beers, providing their outlook on characters, actors and the production process.

Kelly West of CinemaBlend noted that the "seriously extended episodes" were not significantly expanded, only adding a few minutes of extra footage, which don't influence the storyline.