Sydow received a Tony nomination for the 1967 revival of Irvin Berlin’s Annie Get Your Gun, which starred Ethel Merman. Among his other Broadway directorial credits were the musical Sophie as well as The Crucible, which starred Farley Granger, The Imaginary Invalid and A Touch of the Poet for the ANTA Theatre. His last Broadway credit was a production of Sganarelle for the National Theater of the Deaf.
His Off-Broadway work included productions for the American & National Repertory Theatres and he won an Obie Award in 1958 for his theatrical adaptation of The Brothers Karamazov.
As an actor, he was seen in Once Upon a Mattress on Broadway, where he began as a stage manager. (He later directed the touring production, which starred Buster Keaton.) On television, his credits include guest appearances on Frasier, Touched by an Angel, and Brothers and Sisters.
In 1970, Sydow joined the staff of the University of Washington, where he headed the directing program for 16 years.
In lieu of flowers, donations may be made in his name to the Actors Fund of America.