Written by Mark Driscoll and directed by executive producer Debbie Allen, it aired on the American Broadcasting Company (ABC) in the United States on October 22, 2015.

The episode centers around the dinner party hosted by Meredith Grey (Ellen Pompeo), Amelia Shepherd (Caterina Scorsone) and Maggie Pierce (Kelly McCreary).

The episode also follows Arizona Robbins (Jessica Capshaw) as she attempts to adjust to Callie's new relationship, April Kepner (Sarah Drew) as she distracts herself from her ongoing issues with her estranged husband Jackson Avery (Jesse Williams), and a heated argument between Jo Wilson (Camilla Luddington) and Stephanie Edwards (Jerrika Hinton).

On its initial airing, "Guess Who's Coming to Dinner" was watched by a total of 8.96 million viewers and scored a 2.4/8 in the key 18–49 demographic in the Nielsen ratings, ranking at #1 for the time slot.

[1] As guests begin to arrive for the dinner party, Meredith Grey (Ellen Pompeo) answers the door and is shocked to see Callie Torres (Sara Ramirez) and her new girlfriend, Penelope "Penny" Blake (Samantha Sloyan).

Meanwhile, Maggie Pierce (Kelly McCreary) worries she might have contracted an STD from her relationship with Andrew DeLuca (Giacomo Gianniotti) and rushes to the hospital for a test, leaving her dinner responsibilities behind.

Meanwhile, Amelia Shepherd (Caterina Scorsone), devastated to realize she had been friendly with one of the doctors responsible for Derek's death, demands that Penny recount every detail of the night he died.

Her intense reaction leads to a confrontation that ends with Amelia kicking Penny out of the house just as Callie and Owen Hunt (Kevin McKidd) return from the hospital.

[10] The episode ranked as the top TV show in the 8:00 p.m. time slot, outperforming Fox's Bones, NBC's Heroes Reborn and The CW The Vampire Diaries.

The site enjoyed the dynamic between Meredith, Alex Karev (Justin Chambers), Amelia, and Owen Hunt (Kevin McKidd), appreciating their evolving relationships.

"[13] Entertainment Weekly's Ariana Bacle praised the episode for embodying the drama, emotion, and suspense of "Old Grey's", highlighting the importance of Alex's role as Meredith’s "person" after Cristina Yang's (Sandra Oh) departure.