This study was conducted to assess the efficacy of d-Norgestrel associated with Ethinylestradiol (Neogynon 21) as postcoital contraception and to report on the clinical experience obtained with this type of contraception. 323 women were treated during 72 h. period following unprotected intercourse. All subjects received 0,2 mg Ethinylestradiol and 1 mg d-Norgestrel (Levonorgestrel) in 2 equally divided doses 12 hours apart. - 1 mg Levonorgestrel was observed to be as effective as 2 mg of the racemic Norgestrel. PCC given during the first part of the cycle, shortened the latter in 80% of relevant cases. Nausea occurred in 30.3% of all patients; among these 14.2% also mentioned vomiting. Three pregnancies occurred of which only one could be attributed to method failure. The corrected failure rate is thus estimated at 0.3%.