The authors report their experience with fine needle chorionic villus sampling carried out transabdominally. Six hundred antenatal karyotype diagnoses were made using this method. The indications were: maternal age: 509 (85%), previous chromosomal abnormalities: 57 (9.5%), parental chromosomal abnormalities: 19 (3%), X chromosome linked diseases: 9 (1.5%), others: 6 (1%). The patients were divided into two groups according as to whether the test was carried out before or after 12 weeks of amenorrhea (Group 1 and Group 2). Each group was divided into two sub-groups according to whether the amniotic membranes were broken or not. The test was carried out using a 20 gauge needle under ultrasound control with a to-and-fro movement using continuous aspiration. The success rate was 98.4%. Minor complications were rare. Contractions 9 (1.5%), spotting 4 (0.6%), small haematomas 13 (2.1%), loss of amniotic fluid 4 (0.6%). The level of unintentional abortions depended on the duration of the pregnancy and whether the amniotic cavity or not was entered. In group 1 (before or at 12 weak amenorrhea) there were 2 abortions out of 124 cases (1.6%) and if the needle entered the amniotic cavity 10 out of 57 cases (17.5%). In group 2 (after 12 weeks of amenorrhea) there was no ill effect from going into the amniotic cavity to the rest of the pregnancy. The abortion rates was 6 out of 419 (1.43%). There were no false positive or negative results.(ABSTRACT TRUNCATED AT 250 WORDS)