Purpose: We investigated the efficacy and safety of weekly paclitaxel monotherapy in previously treated patients with advanced gastric cancer (AGC) and poor performance status (PS) according to the Eastern Cooperative Oncology Group (ECOG). Patients and Methods: Patients with evaluable disease who failed at least one previous chemotherapy and had a PS of 2–3, received paclitaxel 70 mg/m2 on days 1, 8 and 15 every 4 weeks. Results: The median overall survival (OS) was 5.5 months (95% confidence interval, CI, 3.3–7.8) and progression-free survival was 2.1 months (95% CI, 1.2–3.0). The overall response rate was 3.8% and the disease control rate was 25.0%. Treatment-related toxicities were tolerable. OS was 7.1 (95% CI, 5.4–9.5) and 3.7 months (95% CI, 2.1–5.3) for patients with PS-ECOG 2 and 3, respectively (p < 0.001). When evaluated according to the previous treatment, OS was 5.1 (95% CI, 3.3–7.0) and 6.5 months (95% CI, 3.8–9.3) for patients receiving two and three or more lines of treatment, respectively (p = 0.815). With multivariate analysis, PS was a significant factor for OS. Conclusion: Survival in patients treated with weekly paclitaxel monotherapy was comparable to other second- or third-line chemotherapies for AGC, with acceptable toxicities in previously treated patients with poor PS.