Male factors in spontaneous abortion were discussed in a literature survey based upon human and animal studies including certain biological (andrological, chromosomal, immunological) and psychosocial factors (civil status, marital relation), psychological reactions after the abortion as well as different psychosomatic interrelations. Probably the abortion risk is raised by negative influences of stress upon male sex hormones, immun- and spermaparameters. According to the results, male factors should be taken into account in the diagnosis of spontaneous abortion more frequently. Moreover further study is required for the precise determination of the different factors.