The reproductive effect of N,N-dimethylformamide (DMF) administered epicutaneously to rats was examined. The rats were dosed on gestation days 6-15 or on gestation days 1-20 at dose levels of up to 2 ml DMF kg-1 body weight. Body weight, weight gain and pregnancy rate were reduced in those rats receiving 2 ml DMF kg-1 body weight per day on days 6-15. A reduction in the number of live fetuses and in fetal weight, as well as an increase in postimplantation loss, were also observed at this dose level. Similar but more pronounced effects were observed in rats dosed on days 1-20 with 2 ml DMF kg-1 body weight. The lowest effect level was 1 ml DMF kg-1 body weight. No other dose-related effects were found in this study.