PURPOSE In-transit disease afflicts approximately 10% of patients with extremity melanoma; no single treatment approach has been uniformly accepted as the most effective. We report long-term outcomes in patients with in-transit extremity melanoma who underwent isolated limb perfusion (ILP) in an era of increasingly accurate staging, uniform operative and treatment conditions, and regular long-term follow-up. PATIENTS AND METHODS Between May 1992 and February 2005, 91 patients (median age, 57 years; 50 women, 41 men) underwent a 90-minute hyperthermic ILP (melphalan, 10 to 13 mg/L limb volume, tumor necrosis factor [TNF; n = 44], or interferon [n = 38]) using uniform operative technique and intraoperative leak monitoring. Patients were prospectively followed for response, in-field progression-free survival (PFS), and overall survival (OS). Parameters associated with in-field PFS and OS were analyzed by standard statistical methods. Results There was one operative death (1.1%). There were 62 complete responses (69%) and 23 partial responses (26%) in 90 assessable patients. At a median potential follow-up of 11 years, median in-field PFS was 12.4 months and median OS was 47.4 months; 5 and 10-year actuarial OS probabilities were 43% and 34%, respectively. Female sex and low tumor burden (< or = 20 lesions) were associated with prolonged in-field PFS (male:female hazard ratio [HR], 2.07; 95% CI, 1.27 to 3.38; 21+ v < or = 20 tumors HR, 2.29; 95% CI, 1.21 to 4.34; P < .011 for both). Female sex was associated with improved OS (P = .027; male:female HR, 1.82; 95% CI, 1.07 to 3.09). CONCLUSION In appropriately selected patients, ILP has clinical benefit. The use of TNF was not associated with improved in-field PFS, while female sex was associated with better survival.