Objective. We assessed the antineoplastic effect and adverse reaction s of pacl itaxel monotherapy with paclitaxel 210 mg/m2 given every 3 weeks by 3-h infusio n on patients with endometrial cancer given as a 3-h infusion. Methods. This st udy was a multi-center, open-label phase II clinical trial of paclitaxel 210 m g/m2 given every 3 weeks by 3-h infusion. Patients with advanced or recurrent e ndometrial cancer were enrolled. The primary endpoint for efficacywas tumor resp onse rate. The secondary endpoints were duration of response and adverse drug re actions. Results. Among 23 patients evaluated for efficacy, partial remission (P R) was achieved in 7, no change (NC) in 10, progressive disease (PD) in 5, and n ot estimable (NE) in 1. The overall response ratewas 30.4%(7/23 cases). In seve n PR cases, median duration of response was 130 days (100-245 days). Subjective or objective symptoms ≥grade 3 included febrile neutropenia and constipation i n 8.7%(2/23 cases) each; and nausea, vomiting, fatigue, pain, urinary tract inf ection, lowered oxygen saturation, anorexia, arthralgia, myalgia, neuropathy, we ight loss, dyspnea, and need for red cell transfusion in 4.3%(1/23) each. Labor atory test abnormalities ≥grade 3 included neutropenia (78.3%, 18/23), leucope nia (47.8%, 11/23), lowered hemoglobin (13.0%, 3/23), decreased potassium (8.7 %, 2/23), and decreased sodium (4.3%, 1/23). All adverse reactions were succes sfully managed by prolonging treatment interval, dose reduction, interrupting ad ministration, discontinuation, and administration of G-CSF. Conclusion. Three- hour intravenous infusion of paclitaxel 210 mg/m2 is useful for endometrial canc er. Antineoplastic effect was achieved and adverse reactions were clinically man ageable. Objective. We evaluated the antineoplastic effect and adverse reaction of paclitaxel monotherapy with paclitaxel 210 mg / m2 given every 3 weeks by 3-h infusio n on patients with endometrial cancer given as a 3-h infusion. Methods. This st udy was a multi-center, open-label phase II clinical trial of paclitaxel 210 mg / m2 given every 3 weeks by 3 -h infusion. Patients with advanced or recurrent endometrial cancer were enrolled. The primary endpoint for efficacy was tumor resp onse rate. The Secondary endpoints were duration of response and adverse drug re actions. Results. Among 23 patients evaluated for efficacy, partial remission (PR) was achieved in 7, no change (NC) in 10, progressive disease (PD) in 5, and not In seve n PR cases, median duration of response was 130 days (100-245 days). Subjective or objective symptoms ≥ grade 3 included febrile neutropenia and constipation in 8.7% (2/23 cases) each; and nausea, vomiting, fatigue, urinary tract infaction, lowered oxygen saturation, anorexia, arthralgia, myalgia, neuropathy, we ight loss, dyspnea, and need for red cell transfusion in 4.3% (1/23) each. grade 3 included neutropenia (78.3%, 18/23), leucope nia (47.8%, 11/23), lowered hemoglobin (13.0%, 3/23), decreased potassium (8.7%, 2/23), and decreased sodium 4.3%, 1/23). All-round reactions were succes sly managed by prolonging treatment interval, dose reduction, interrupting ad ministration, discontinuation, and administration of G-CSF. Conclusion Three-hour intravenous infusion of paclitaxel 210 mg / m2 is useful for endometrial canc er. Antineoplastic effect was achieved and adverse reactions were clinically man ageable.