Purpose: This study was designed to analyze the outcome and toxicity of thoracic radiation therapy (TRT) and chemotherapy for patients who suffer with limited-stage small-cell lung cancer (LS-SCLC). Materials and Methods: We retrospectively studied 35 patients with LS-SCLC. TRT was administered once daily (1.8 to 2 Gy per fraction) and it was directed to the primary tumor for a total 50 to 66 Gy in 6 to 7 weeks. The patients received four cycles of etoposide plus cisplatin. TRT was begun on day 1 of the first cycle of chemotherapy in the concurrent arm and after the fourth cycle in the sequential arm. Results: The median progression-free survival time was 16.5 months (95% confidence interval [CI], 9.0 to 24.1 months) for the sequential arm, and 26.3 months (95% CI, 16.6 to 35.9 months) for the concurrent arm. The 2-year progression-free survival rate was 16.0 percent for the sequential arm and 50.0 percent for the concurrent arm (p=0.0950 by log-rank test). Leukopenia was more severe and more frequent in the concurrent arm than in the sequential arm. However, severe esophagitis was infrequent in both arms. The radiotherapy was interrupted more frequently in the concurrent arm than in the sequential arm due to hematologic toxicities (p=0.001). Conclusion: This study suggests that concurrent TRT with etoposide plus cisplatin is more effective for the treatment of LS-SCLC than sequential TRT. However, there is a significant increase in the risk of toxicities, and radiotherapy was frequently interrupted in the concurrent arm due to hematologic toxicities.