Easygoing expatriate Jack Flowers (Ben Gazzara) makes his living in early-1970's Singapore legally and illegally looking after the needs of American and British businessmen, such as the mild-mannered William Leigh (Denholm Elliott). With his gift for putting clients and girls at ease, Jack opens a successful brothel, but pressure from local mobsters soon puts him out of business. Ever the survivor, he starts working for the shady, Cuban-cigar-smoking Eddie Schuman (Peter Bogdanovich) as a pimp for GI's on breaks from Vietnam. But Jack's conscience starts to dog him when Schuman hires him to take compromising pictures of a visiting Senator (George Lazenby). 'Saint Jack' offers a pimp with a heart of gold, who is less an ugly colonial American abroad than an outsider trying to make the best of a bad situation.