Aim: We developed a scale to measure the social activities of community-dwelling older men requiring support. Methods: The participants were a group of 134 men, ≥65 years old, who required support and were living in Hokkaido, Japan. An anonymous questionnaire was administered through individual interviews. Valid responses were obtained from 121/134 interviewees. The construct validity of the resulting scale was assessed by exploratory factor analysis (EFA). Criterion-related validity was tested with Spearman’s rank correlation test based on the Social Activities Index for Elderly People (SAI-E). Reliability was assessed by Cronbach’s alpha. Results: A Social Activities Scale for Community-dwelling Older Men Requiring Support (SASOMS) scale was created, comprised of the following three subscales: daily interactions with familiar people;intimate relationships with family members;and interactions with others through activity programs (e.g., exercise, games, recreation, etc.). The created SASOMS scale correlated with the SAI-E (r = 0.557), and its criterion-related validity was confirmed. The alpha coefficient of the new scale was 0.791, and its internal consistency was confirmed. Conclusions: The reliability and validity of the developed SASOMS scale was confirmed, demonstrating that it can be used to assess social activities specifically in older men requiring support. Our results suggest that the scale can be used effectively by care providers who support older men requiring care. The usability of the SASOMS should continue to be improved, and it is necessary to verify its validity in longitudinal studies.