Sixty-six couples who made direct application or were referred to the sexual dysfunction unit of the Department of Psychiatry, Medical School of Ankara University, Turkey, during a one year period were assessed for their suitability for sex therapy. Suitable couples were treated for the present sexual dysfunction. The assessment for suitability included detailed interviews, physical and laboratory screening for possible organic causes of sexual dysfunction. Among those couples where the presenter (the partner with the sexual problem) did not show any evidence of organic cause, the assessment focused on the nature of sexual dysfunction, motivation of each partner for treatment, marital and relationship problems and present or past psychiatric disorders. Organic causes were found in almost one-sixth of the presenters and over 50% of the couples were found to have significant marital and sexual problems. The couples that were found to have an organic cause for sexual dysfunction were excluded from the study and marital therapy in conjunction with sex therapy was offered to couples with marital problems. Those couples who completed their course of treatment were evaluated in terms of how prognosis was effected by pre-treatment measures such as the nature of the sexual dysfunction, motivation of each partner, quality of marital relationship and compliance with homework assignments.