Arm lymphedema after breast cancer therapy has been treated with various forms of conservative and surgical treatment during recent years. The clinical results usually have been modest or, in some instances, even disappointing. In a previous series of patients treated with the new liposuction technique combined with controlled compression therapy, we found, however, an overall edema reduction of 106 percent after 1 year. The purpose of this study was both to investigate how much the surgical procedure contributes to the outcome and to clarify the importance of controlled compression therapy. Twenty-eight patients were, therefore, prospectively matched into two groups. One group received liposuction combined with controlled compression therapy, and one group received the therapy alone. Additionally, the therapy group was compared with our complete group of patients treated thus far with liposuction combined with therapy (n = 30). The prospective study using matched pairs (n = 14) showed that liposuction combined with controlled compression therapy is significantly more effective than the therapy alone (p < 0.0001), with a mean difference of about 1000 ml during the entire 1-year observation period. The beneficial effect of liposuction was confirmed by the comparison between the controlled compression therapy group and our complete group of patients treated with liposuction combined with the therapy, as the edema reduction figures after 1 year were 47 percent and 104 percent, respectively (p < 0.0001). In six patients who had surgery and a complete reduction of the edema, the compression garments were removed for 1 week, 1 year postoperatively. A marked increase in the arm volume was observed, which was immediately remedied by reapplying the garments. We conclude that liposuction combined with controlled compression therapy reduces arm lymphedema more efficiently than the therapy alone. Continued use of compression garments is, however, important to maintain the primary surgical outcome.