In an open, single-group, phase III clinical trial of 5 years, the clinical performance of NOVA T 380 was investigated in three centers. The device having a higher copper surface of 380 mm(2) is a modification of NOVA T. A total of 400 voluntary women were enrolled in the study. The mean age was 31.4 years (SD 5.5) with the minimum of 18 and the maximum of 44 years. At the end of the study, 211 women had passed the 60-month visit. Cumulative discontinuation rates at the end of the first and the fifth year calculated by Kaplan-Meier estimates, were respectively as follows: pregnancy 0.5 and 1.9, expulsion 1.3 and 4.1, bleeding 4.4 and 14.0, pain 1.3 and 4.2, removal for other medical reason 1.4 and 6.4, planning pregnancy 0.8 and 13.5, and removal for other personal reason 2.4 and 11.9 per 100 users. Neither ectopic pregnancies nor episodes of pelvic inflammatory diseases (PIDs) occurred. One perforation was recorded; the calculated rate is 0.3 per 100 women (first year). The continuation rate was 88.3 and 52.5 at 1 and 5 years, respectively. In conclusion, the 5-year performance of NOVA T 380 was good compared to other "high-loaded" copper devices. Safety was acceptable over the entire study period.