BACKGROUND Paclitaxel is a diterpenic plant product that has significant activity in several solid tumors, including epithelial ovarian cancer. After promising results in Phase I and II studies, its use has increased dramatically. With this increased use, isolated reports of local tissue reactions to paclitaxel have been described. The purpose of this study was to characterize further the presentation and clinical course of this toxic effect. METHODS Nine hundred fifty-five courses of paclitaxel were administered to patients with gynecologic malignancies at M. D. Anderson Cancer Center during a 13-month period. Nineteen (2%) local infusion-site injuries in 17 patients were observed. RESULTS The primary disease site was the ovary in 13 patients, the peritoneum in 2, and the endometrium in 2. Paclitaxel was administered as initial therapy in 6 patients and as salvage therapy in 11. Clinical evidence of infiltration was documented during infusion in 8 of 19 (42%) reported episodes. Immediate reactions consisting of mild discomfort, erythema, and edema were observed in six patients, three of whom had complete resolution of the lesion within 1 month. The remaining patients noted initial development of injury between 3 and 13 days after paclitaxel infusion. The typical injury was a discolored, raised, rounded, and indurated lesion that was moderately painful. Two patients (11%) had Grade 1 lesions, 13 (68%) had Grade 2 lesions, and four (21%) had Grade 3 lesions with central ulceration. Cellulitis requiring intravenous antibiotic therapy was associated with two lesions. At last follow-up, 13 injuries had persistent discoloration and induration; one patient had persistent ulceration present at the time of her death 6 months after presentation and one patient underwent excision of a persistent lesion at 12 months. CONCLUSIONS Given the incidence of Grade 2 and Grade 3 local reactions, it appears that paclitaxel should be considered a vesicant.