Occupational factors in spontaneous abortions are reviewed and discussed in terms of difficult working conditions (physical and psychological strains) and exposition to noxious agents in women and men. The discussion was based upon clinical, epidemiological and biological studies. The results showed elevated abortion risks in different occupational groups. Risk factors for both partners were hard physical work, psychological and socio-economic stress, some chemicals, metals and pharmacological products. Animal studies demonstrated time- and dose-dependent effects on embryonic and fetal development as well as accumulation and potentiation of teratogenic agents. Chronic and multifactorial occupational effects seem to be very important and need further occupational effects seem to be very important and need further study.