Abstract Linear alkylbenzene sulphonate (LAS) was applied daily, during the gestation period, to the clipped skin of pregnant rats. Concentrations of 0·05, 0·1 and 0·5% active ingredient were applied and allowed to remain on the skin; concentration of 1, 5 and 20% active ingredient were applied and removed after a 30-min exposure period. Three control groups were included in the study: one received no treatment, the second was clipped only, and the third was clipped and vehicle was applied to the exposed dermis by the method used for the continuous exposure groups. All females were killed at day 21 of gestation, the maternal rats were examined grossly, and the foetuses were examined in detail. The only effects attributed to LAS in this study were reduced body weights in the dams given the highest level and skin changes in the dams that received the two highest concentrations (5 and 20% for 30 min). These effects included erythema followed by skin thickening and fissuring. These observations were marked at the 20% level and slight at the 5% level. There were no findings indicative of effects of LAS on the foetal parameters evaluated. Specifically, there was no indication of teratogenic or embryotoxic effect from LAS.