When he moved to Los Angeles in 1996,[3] he opened a gallery called Room 702 in Hollywood with his classmate Brent Petersen and started showing and working with other artists.

[1] Despite an invitation to move into the 6150 complex on Wilshire Boulevard—which already housed other renowned galleries[4]—Room 702 closed after less than two years, and Grotjahn became a full-time artist.

[6] The way Grotjahn paints grew out of conceptual sign making; he would faithfully reproduce peculiar graphics and phrases from local storefronts in his native Los Angeles.

[1] Grotjahn stopped painting the Butterfly works in 2008, after tearing his rotator cuff and breaking a shoulder bone after hitting an ice patch[14] in a ski accident.

A series of large, vertical Face Paintings is based on the simple geometric structure of the eyes, nose, and mouth.

[16] Grotjahn's mask sculptures extend the artist's idiosyncratic investment in the process and ritual of painting into three dimensions.

[14] In 2010, Grotjahn's oil on linen painting Untitled (Lavender Butterfly Jacaranda over Green) (2004) was sold for $1.5 million against its presale estimate of $500–700,000 at Christie's New York.

[30] On May 17, 2017 a new price record was set for a Grotjahn work at auction when “Untitled (S III Released to France Face 43.14)” was sold for $16.8 million dollars .

The biggest sale in dispute took place in 2008 at Phillips de Pury & Company in New York, when Valentine sold Untitled (Blue Face Grotjahn) (2005) for $1,217,000,[33] including premium.