She played Sarah Jane, a young African-American woman, in Imitation of Life (1959), for which she was nominated for an Oscar as Best Supporting Actress.

[6][7][8][9] Most of Kohner's film roles came during the late 1950s and early 1960s, including co-starring with Sal Mineo in both Dino (1957) and The Gene Krupa Story (1959).

In her best-known role, Kohner played Sarah Jane in Imitation of Life, portraying a light-skinned black woman who "passes" as white.

The expensive, glossy Ross Hunter production, directed by Douglas Sirk and starring Lana Turner, was a box-office hit.

Following her role in Imitation of Life, Kohner appeared in All the Fine Young Cannibals opposite Natalie Wood and Robert Wagner.

On April 23, 2010, a new print of Imitation of Life (1959) was screened at the TCM Film Festival in Los Angeles, California, to which Kohner and co-star Juanita Moore were invited.