Objectives: Examine the social influence of adult children on the cardiovascular-related health behaviors of older South Asian (SA) immigrants to inform lifestyle interventions.Design: This mixed-methods study used data from an ancillary study of social networks (2014-2018) in the Mediators of Atherosclerosis in South Asians Living in America cohort. Phase 1 was a quantitative analysis of self-reported diet and physical activity among SA adults (n = 448, mean age = 58 years, SD 8.4) who named at least one adult child to their social network. The Alternative Healthy Eating Index (AHEI) was used to measure parents' diet; higher numbers indicate a healthier diet (range 0-110). Phase 2 was a thematic content analysis of in-depth qualitative interviews from a subsample of these parents (n = 23, mean age = 55, SD 7.6).Results: Parents with an adult child in their network who consumed uncooked vegetables daily had mean parental AHEI score 1.5 points higher (adjusted p-value = 0.03) than those who had a child in the network who ate uncooked vegetables less often. When at least one adult child in their network ate fresh fruit daily compared to less frequently or when at least one child ate non-SA food daily compared to less frequently, mean parental AHEI scores were higher by 2.0 (adjusted p-value = 0.01) and 1.6 (adjusted p-value = 0.03) points respectively. Parents with an adult child in their network who exercised at least weekly were more likely to meet guideline-recommended physical activity levels than parents with children who exercised less often (76% v. 56%, adjusted p-value = 0.02). Adult children provided social support and were seen as 'role models' for healthy behavior, especially when adopting Western health behaviors.Conclusion: Positive role modeling and support from adult children were important facilitators of healthy behavior change in older SA immigrants and can inform health behavior interventions for SA adults.