Idina Menzel played a brief love interest of Tim Daly's character (Pete) in Season 2 when in reality, she was married to Taye Diggs (Sam). There's even a scene of Sam approving of Pete dating Idina's character.

The role of Naomi Bennett was played by Merrin Dungey in the pilot episode's Grey's Anatomy: The Other Side of This Life, Part 1 (2007) and Grey's Anatomy: The Other Side of This Life, Part 2 (2007).

The girl painting in Violet's living room is the same painting in the doorway of the Gilmore Girls (2000) home.

The character Sam Bennett's nickname/pen name Dr. Feelgood is most likely a reference to the album 'Private Practice' by the band Dr. Feelgood released in 1978.

Alexandra Holden plays 2 different characters on Grey's Anatomy (2005) (as Jamie) and Private Practice (2007) (as Laura). Both characters are the patient of Dr. Addison Montgomery (Kate Walsh).

Debra Mooney plays 2 different characters on Grey's Anatomy (2005) (as Mrs. Hunt, Owen Hunts mother Grey's Anatomy: Here's to Future Days (2009) ) and Private Practice (2007) (as Sylvie in Private Practice: In Which Addison Has a Very Casual Get Together (2007) ).

In the Grey's Anatomy version of the Private Practice pilot (GA-S03E22-23) Shavon Kirksey was the actress who portrayed Maya Bennett, instead of the actress, GeffriMaya, who was actually cast in the series, Private Practice.

Actress Caterina Scorsone (Amelia Shepherd) was really pregnant during season 5. In real life she had a healthy baby girl.

Sarah Drew plays 2 different characters on the "Private Practice"/"Grey's Anatomy" universe (as Judy, a young, pregnant college student in Private Practice), and Grey's Anatomy (2005) (as Dr. April Kepner, a series regular since season 6 on Grey's Anatomy).

Even though the specific reasons behind the shocking choice of killing Pete off-screen between season 5 and 6 haven't been revealed, interviews and statements given by creator Shonda Rhimes and Tim Daly (who is still angry about it) suggest that it was mostly a economic decision because the network cut down some of the budget of the show going into a final season.

Amanda Foreman plays 2 different characters on "Private Practice" (as Katie Kent, Violet's patient, who attacked her (the end of season 2)), and on Grey's Anatomy (2005) (as Nora, wife of a guy with no arms (season 7)).