Ko Hon Man participated in amateur theatre productions since he was in secondary school. He joined the Far East Theatrical Arts Troupe as an actor in the 70's, and studied Chinese and Oriental Dance in the South East Asia Dance Troupe in the 80's. He appeared in the HKRep's production Sunrise in 1980, became a full time actor in 1986 and was the Principal Actor until its corporatization.

Ko Hon Man played in over a hundred productions, including De Ling and Empress Dowager Ci Xi, Small Ripples in a Dead Pool, Ricky My Love, Oedipus the King, An Absolute Turkey, 2000 Syndrome, Crossings, Let Me Love Once, The Crucible, Hong Kong for Sure!, Secret of Resurrection, A Dream Like a Dream, Love In a Fallen City, www.com, Tomorrow Is Another Day, The Eccentricities of a Nightingale, Haunted, Haunted Little Star, Departure 00:00, Sweet & Sour Hong Kong, A Small Family Business, Peach Blossom Fan , The Importance of Being Earnest, Rotate 270¢X, February 14 , Zheng He and The Emperor, (Rep 2 Series) The Cat & I and Peter Pan. He was also the assistant director and the choreographer's assistant of Miss To Sup-neung. And he was the assistant director of Love in a Fallen City 06.

He appears in motion pictures, including I Have A Date With Spring, One of the Lucky Ones, An Umbrella Story, Love a la Zen, The Chinese Feast and Eternal Love. He was the voice-dubbing artist of several motion pictures, including Star Wars I,II,III , Stuart Little 2 , Cats & Dogs and The Polar Express etc. He is the designated vocal artist in the HK edition of the Beast in Walt Disney's Beauty and the Beast and ¶Ì¤j¿ß in Warner Brothers' cartoon features.

He was nominated the Best Supporting Actor (Tragedy / Drama) at the 2003 HK Drama Awards for his work of Qing Longzi in Secret Of Resurrection.