Purpose Considering promising results in phase II studies, a randomized phase III trial was designed to assess the efficacy of adding bevacizumab to first-line cisplatin plus etoposide for treatment of extensive-disease (ED) small-cell lung cancer (SCLC). Patients and Methods Treatment-naive patients with ED-SCLC were randomly assigned to receive either cisplatin plus etoposide (arm A) or the same regimen with bevacizumab (arm B) for a maximum of six courses. In the absence of progression, patients in arm B continued bevacizumab alone until disease progression or for a maximum of 18 courses. The primary end point was overall survival (OS). Results Two hundred four patients were randomly assigned and considered in intent-to-treat analyses (103 patients in arm A and 101 patients in arm B). At a median follow-up of 34.9 months in arm A and arm B, median OS times were 8.9 and 9.8 months, and 1-year survival rates were 25% and 37% (hazard ratio, 0.78; 95% CI, 0.58 to 1.06; P = .113), respectively. A statistically significant effect of bevacizumab on OS in patients who received maintenance was seen (hazard ratio, 0.60; 95% CI, 0.40 to 0.91; P = .011). Median progression-free survival times were 5.7 and 6.7 months in arm A and arm B, respectively ( P = .030). Regarding hematologic toxicity, no statistically significant differences were observed; for nonhematologic toxicity, only hypertension was more frequent in arm B (grade 3 or 4, 1.0% v 6.3% in arms A v B, respectively; P = .057). Conclusion The addition of bevacizumab to cisplatin and etoposide in the first-line treatment of ED-SCLC had an acceptable toxicity profile and led to a statistically significant improvement in progression-free survival, which, however, did not translate into a statistically significant increase in OS. Further research with novel antiangiogenic agents, particularly in the maintenance setting, is warranted.