Participation rates of older people in resistance training (RT) are low despite increasing research showing many health benefits. To increase the number of older people participating in RT it is important to know what would motivate people to become involved, what motivates those who participate to continue, and the factors preventing many older people from commencing participation. To investigate these issues, a questionnaire was mailed to three groups of older people: (1) those receiving home care services, (2) members of a peak non-government seniors' organisation and (3) those participating in a specific gym-based RT programme. In total, 1327 questionnaires were returned (response rate = 42.5%). To feel good physically and mentally were the main reasons motivating participation among all three groups, and falls prevention was identified as an important motivator for the home care respondents. Pain, injury and illness were the main barriers to participating, or continuing to participate. However, medical advice was a factor influencing participation commencement. The results suggest organisations providing RT programmes for older people should tailor the promotion and delivery of programmes to address key motivators and barriers specific to each group to increase the proportion of older people initiating and continuing to engage in RT.