Fincoid, a new copper IUD, was tested on a single clinic basis in a preliminary series of 956 1st insertions and 10,015 woman-months of use with an individual follow-up of 12 months. 458 (48%) of the women were nulliparous and 498 (52%) were parous. About 1/3 of the women had previously discontinued the use of other types of IUDs (mostly copper) because of side effects. The 1st segment of net cumulative rates for the whole series were: pregnancy 1.1, expulsion 4.7, removal for bleeding and/or pain 7.6 and removal for infection 0.8. The continuation rate was 78.9 and the percentage lost to follow-up was 2.8%. The parous group had a higher continuation rate (81) than the nulliparous group (76). Rates for pregnancy, expulsion, and infection in the nulliparous group were about 2-fold the corresponding rates of the parous group. There was no difference in the removal rate for bleeding and/or pain between the 2 parity groups. The results of the study show that the Fincoid is a valid method of intrauterine contraception.