Problem-solving therapy (PST) is a brief, structured psychological treatment. Preliminary clinical findings regarding the effectiveness of PST for treating psychological distress experienced by Japanese cancer patients are presented. Our actual clinical experience in administering PST to four consecutive distressed cancer patients was reviewed. All of the patients were breast cancer survivors who were referred to us after undergoing surgery. Three cases received six PST sessions each and one case received three PST sessions. The depression and anxiety scores decreased after PST. Our preliminary experience suggests that PST is an effective treatment for alleviating psychological distress in Japanese cancer patients and that this treatment should be further examined in a clinical trial.