A survey completed by managers of 77 senior centers in Idaho revealed that meals, blood pressure screening, and games and trips were the most successful activities offered. Alzheimer's support groups, library books for loan, and exercise classes were the least successful. Possible reasons for the success or failure of these activities were explored, and three general implications were drawn: (1) senior citizens like to have fun and socialize without having to bother with preparations; (2) activities offered need to reflect a wide variety of options to elicit large participation and success levels; and (3) senior citizen activities should reflect the needs of each community. References are included. (TE)