One hundred and seven breast cancer patients underwent subcutaneous mastectomy and immediate reconstruction with a subcutaneously-placed, round, saline-filled prosthesis with a textured surface. The primary aim of this prospective study was to determine the frequency of capsular contracture in both irradiated and non-irradiated breasts after this operation. Two different types of round implants with different pore sizes on their textured surfaces, Siltex and Microcell, were randomly chosen. Twenty-four patients received radiotherapy within the first year following the operation. Capsular contracture was measured by the Baker/Palmer classification and by applanation tonometry at regular intervals for 5 years or as long as the patients lived (median 60 months). Twenty-two patients (20.6%) developed capsular contracture, defined as Baker three or four. Sixteen of those were reoperated, 15 with open capsulotomy with or without implant exchange, one with closed compression capsulotomy, and monitored thereafter for 5 years or until death (median 60 months). All 107 patients could be monitored for 2 years, while 87 reported for the 5-year follow-up. The rate of capsular contracture was significantly higher (p=0.01) for irradiated breasts than for non-irradiated ones, 41.7 and 14.5%, respectively. It was slightly higher (p<0.05) for large-pore implants than for those with smaller (and more numerous) pores. There was a good correlation between the two different methods for measuring capsular contracture. None of the 16 reoperated patients had a recurrence of capsular contracture within 5 years. The results indicate a high rate of capsular contracture after this operation, especially when followed by radiation. However, a fairly simple procedure to treat capsular contracture seems to give good long-term results.