Wahlgren's first acting job, at the age of four, was alongside her mother in the television play Den längsta dagen (The Longest Day).

[15] She has also appeared in musical roles in Annie Get Your Gun, Grease, The Wizard of Oz, Cats and Nils Karlsson Pyssling.

[16] On 29 September 2007, The Sound of Music premièred at the Göta Lejon theater in Stockholm, where Wahlgren played in a cast that included Tommy Nilsson.

[18] Between 2018 and 2019, Wahlgren acted in her own stage show celebrating 40-years as a singer and actress, called Kort, glad och tacksam (Short, Happy and Grateful).

[20] In the mid-to-late 1980s, Wahlgren developed a pop music career, touring several times and releasing studio albums.

[29][30] Her 2013 entry was with Jenny Silver and Hanna Hedlund as part of the band Swedish House Wives performing the song "On Top of the World".

[31] Wahlgren has been a television presenter for several shows, including Scenen är din, Söndagsöppet (both on SVT), Småstjärnorna and Baby Boom (both on TV4).

[39][40] In 2019, Wahlgren had a leading role as Santa's wife in Sveriges Television's Christmas calendar, Panik i tomteverkstan, opposite Per Andersson.

[42] In 2023, Pernilla Wahlgren started presenting the SVT show Allsång på Skansen, replacing Sanna Nielsen.