The role that male sexual partners play in the treatment outcome of drug dependent pregnant women deserves greater attention. Pregnant women enrolled in a comprehensive treatment program with drug-free (n=85) or drug-using (n=82) male sexual partners completed a relationship survey and were compared on partner and psychosocial variables. Compared with male drug-free partners, male drug-using partners had more unemployment and more current legal involvement, less education, were less likely to be supportive of the pregnant woman's recovery efforts and were more likely to give them money to buy drugs. Male drug-free partners also had fewer medical, dental, legal and transportation needs than male drug-using partners. Data from treatment retention suggests that women with male drug-using partners are retained in a comprehensive treatment for a shorter time than women with male drug-free partners. A male partner's drug-using status should be considered when treating pregnant drug dependent women.