OBJECTIVE.: METHODS.: RESULTS.: Of the 103 eligible RCTs identified, 58 (56.3%) were funded by industry, 19 (18.4%) were funded by nonprofit sources, 6 (5.8%) had mixed funding, and funding for 20 (19.4%) was not specified. Industry-funded RCTs had significantly more study centers and subjects, while nonprofit agency–funded RCTs had longer duration and were more likely to study different treatment strategies. Outcome could be assessed for 86 (83.5%) of the 103 RCTs studied. The funding source was not associated with a higher likelihood of positive outcomes favoring the sponsored experimental drug (75.5% of industry-funded RCTs had a positive outcome, compared with 68.8% of non-industry–funded RCTs, 40% of RCTs with mixed funding, and 81.2% of RCTs for which funding was not specified). Industry-funded RCTs showed a trend toward a higher likelihood of nonpublication (P = 0.093). Industry-funded RCTs were more frequently associated with double-blinding, an adequate description of participant flow, and performance of an intent-to-treat analysis. CONCLUSION.