Introduction: Most patients with limited disease small cell lung cancer (LD-SCLC) receive definitive radiochemotherapy. Some patients cannot withstand combined modality treatments. Patients with short life expectancies should receive less time-consuming programs. For patients with favorable prognoses, cure while avoiding late toxicity is important. Personalized treatment programs are required. An instrument to estimate the survival after radiochemotherapy of LD-SCLC was created. Methods: Seventy-one patients receiving definitive radiochemotherapy for LD-SCLC were retrospectively analyzed. Eight factors were evaluated for survival including gender, age, Karnofsky performance score, T-stage, N-stage, tumor substage, number of pack years, and pre-radiotherapy hemoglobin level. Factors that were significant (p < 0.05) or showed a trend (p ≤ 0.08) on multivariate analyses were incorporated in the score. Scoring points were derived from 2-year survival rates divided by 10 and added to scores for individual patients. Results: On multivariate analysis, gender (p = 0.03), performance score (p < 0.001), and pre-radiotherapy hemoglobin level (p = 0.04) were significant, and tumor substage showed a trend (p = 0.08). Taking into account the 2-year survival rates of these factors, scores for single patients ranged from 9 to 26 points. Three groups were identified: 9–13, 14–18, and 19–26 points. One-year survival rates were 8, 73, and 100 %, respectively (p < 0.001). Two-year survival rates were 0, 35, and 87 %, respectively (p < 0.001). The 3-year survival rates were 0, 19, and 75 %, respectively (p < 0.001). Conclusion: This score including three groups with significantly different survival rates is a helpful instrument for personalization of therapy for patients with LD-SCLC. When using this instrument, the limitations if this study must be taken into account.