Objectives: Sodium reduction in restaurant foods is important because 77% of sodium in the United States is consumed by eating prepared and restaurant foods. We evaluated a sodium-reduction intervention, Healthy Chinese Take-Out Initiative, among Chinese take-out restaurants in low-income neighborhoods in Philadelphia, Pennsylvania. Our objectives were to (1) analyze changes in the sodium content of food samples and (2) collect data on changes in chefs��� and owners��� knowledge about the health risks of sodium overconsumption, perceptions of the need for sodium reduction, self-efficacy for lowering sodium use, and perceptions of training needs for sodium-reduction strategies. Methods: The initiative trained chefs from 206 Chinese take-out restaurants on strategies to reduce sodium in prepared dishes. We analyzed changes in the sodium content of the 3 most frequently ordered dishes���shrimp and broccoli, chicken lo mein, and General Tso���s chicken���from baseline (July-September 2012) to 36 months after baseline (July-September 2015) among 40 restaurants. We conducted a survey to examine the changes in chefs��� and owners��� knowledge, perceptions, and self-efficacy of sodium reduction. We used multilevel analysis and repeated-measures analysis of variance to examine effects of the intervention on various outcomes. Results: We found significant reductions in the sodium content of all 3 dishes 36 months after a low-sodium cooking training intervention (coefficients range, ���1.06 to ���1.69, P < .001 for all). Mean knowledge (range, 9.2-11.1), perceptions (range, 4.6-6.0), and self-efficacy (range, 4.2-5.9) (P < .001 for all) of sodium reduction improved significantly from baseline (August 2012) to posttraining (also August 2012), but perceptions of the need for sodium reduction and self-efficacy for lowering sodium use returned to baseline levels 36 months later (August 2015). Conclusions: The intervention was a useful population health approach that led to engaging restaurants in sodium-reduction practices. Local public health agencies and professionals could partner with independent restaurants to introduce environmental changes that can affect population health on a broad scale, particularly for vulnerable populations.