Objective: The purpose of this investigation is to examine correlates and predictors of self-care activities for persons diagnosed with arthritis both cross-sectionally and longitudinally. Method: Data from telephone surveys conducted with 313 older (M = 68.8, SD = 8.93) individuals, chosen from a larger sample, who reported professionally diagnosed arthritis, were used. Results: A total of 10 of the 11 self-care activities changed significantly during the 1-year interval, with 9 showing increased participation. Results from hierarchical regressions showed that all three blocks of predictors explained significant portions of variance, with gender and perceived importance of general health significantly predicting self-care activities at Time 1, at Time 2, and longitudinally. Discussion: These results highlight the influence of demographic, health status, and health belief variables on self-care both cross-sectionally and longitudinally. Future work should focus on the mediating effects of these and other variables to better understand the processes by which individuals engage in self-care behavior.