Reproductive tracts from 89 3-year-old female river otters (Lutra canadensis), from Louisiana were examined. Eighteen of these were in a reproductive phase out of synchrony with the expected population norms. Eight of 32 otters had fewer embryos than corpora lutea, indicating intrauterine mortality in 25% of the sample. Chemical analyses of liver tissue from 57 otters revealed a low prevalence of polychlorinated biphenyls (PCB) and organochlorine pesticide contamination. These low levels of organochlorine compounds were not associated with atypical reproductive synchrony or intrauterine mortality.