OBJECTIVES: The purpose of the study was to assess the effect of exposure to persistent organochlorine compounds through the consumption of fatty fish from the Baltic Sea on human fertility. METHODS: Information on time to pregnancy, miscarriages, and subfertility was collected retrospectively by self-administered questionnaires in two cohorts of fishermen`s sisters from the Swedish east coast, by the Baltic Sea, and the west coast, where fish are less contaminated. Along with cohort affiliation, fish consumption and growing up in a fishing village or fisherman`s family were used as measures of exposure within the eastcoast cohort (ie, the exposed cohort). RESULTS: There was no support for a negative effect of the consumption of fatty Baltic Sea fish on time to pregnancy, miscarriages, or subfertility. On the contrary, some evidence pointed towards a protective effect of fatty fish consumption within both cohorts. CONCLUSIONS: No evidence of reduced fertility was found for women who could be assumed to have a high lifetime consumption of fatty fish contaminated by persistent organochlorine compounds. A possible explanation for this finding is that a positive effect of some of the constituents in fatty fish could be strong enough to disguise the hazardous effects of exposure to persistent organochlorine compounds.