Maurstad graduated from the Royal Academy of Dramatic Art (RADA) in London in 1949.

Maurstad was considered perhaps the greatest interpreter of Henrik Ibsen's Peer Gynt, having played the part numerous times (he even performed excerpts from the play as late as the 2002 Winter Olympic Games in Salt Lake City).

[citation needed] Maurstad's only American film appearance was the 1970 box office and critical disappointment Song of Norway, a musical about the life of composer Edvard Grieg co-starring Florence Henderson.

A testament to his position in Norwegian theatre came when in the 1970s he co-starred with Liv Ullmann in a critically acclaimed Broadway-staging of Ibsen's A Doll's House in New York City.

He married his third wife, actress Beate Eriksen, on New Year's Eve 1999, when she was 39 and he was 73.