We examined the effect of social engagement (SE) on mortality in 30,070 long-stay nursing home residents who were > or =65 years of age and did not have a serious communication problem. Information on SE and resident characteristics were obtained from the Minimum Data Set, and death information was obtained from the National Death Index. Life table analyses show that greater levels of SE are associated with longer survival (P=.0001). Adjusted proportional hazards regression results show that for each increase in the SE scale, residents are 0.94 (range 0.92-0.95) times as likely to die during the follow-up period, independent of known factors associated with mortality. Future studies are needed to understand psychological and other factors related to residents' capacity and motivation for social engagement that could increase quality and quantity of life in nursing home residents.