Robert Vaughn as Napoleon Solo

David McCallum as Illya Kuryakin

Barry Sullivan as Dr. Robert Kingsley

Eleanor Parker as Margitta Kingsley

Leslie Nielsen as General Maximilian Harmon

Leo G. Carroll as Alexander Waverly

Tony Bill as Steven Garrow

Peter Mark Richman as Mr. Webb

Albert Paulsen as Dr. Kurt Erikson

Inger Stratton as Anna Erikson

Hugh Marlowe as Grant

Amy Thomson as Miss Carla