Between 1989 and 1994 first trimester transcervical chorionic villus sampling was offered to 158 patients after proper counselling. The gestational age range was 9-12 weeks. The most important indication was advanced maternal age (75.4%). Adequate sampling after two, and a maximum of three attempts, was achieved in 98% and 99.3% of patients respectively. After the first year of the study karyotyping using the direct method alone was successful in 96% of cases. The success of karyotyping cultures was 98%. Excluding one false positive result the rate of fetal karyotypic abnormalities was 4.8%. 5 spontaneous abortions occurred (3.2%), all in patients of advanced maternal age. Moderate or severe vaginal bleeding occurred in 6.7% of the patients. There was no case of chorioamnionitis.