Background <p>Motivation to engage in physical activities is a multifaceted phenomenon influenced by numerous individual, social, and environmental factors. Understanding these factors in the older adults, as a group with specific needs, is particularly crucial. This study aims to determine the relationship between lifestyle and participation motivation in physical activity among the older adults.</p> Methods <p>This cross-sectional study was conducted from January 2023 to June 2024. A total of 263 older adults visiting comprehensive health centers and day care centers participated in the study. Data were collected using “the Participation Motivation Questionnaire of Older Adults in Physical Activity“(<b>PMQOA</b>) and “Lifestyle older adults” questionnaires. Data were analyzed using univariable and multivariable logistic regression analyses performed in STATA. Odds ratios (ORs) were calculated with 95% confidence intervals (CI).</p> Results <p>The mean score (standard deviation) for motivation to participate in physical activities was 110.3 (19.2) with a (95% CI: 107.9 to 112.6). The mean lifestyle score (standard deviation) was 154.2 (25.4) with a (95% CI: 151.1 to-157.3). The logistic regression results indicated that lifestyle had a positive and significant effect on motivation for physical activities (OR = 1.18, 95% CI: 1.08 to 1.29, <i>p</i> &lt; 0.001), with each unit increase in lifestyle score associated with an average 18% increase in motivation for physical activity. Additionally, older men and those with higher education had greater motivation for physical activity (<i>p</i> &lt; 0.05).</p> Conclusion <p>The results indicate that older adults with a healthier lifestyle have greater motivation to engage in physical activities. It is recommended to implement lifestyle-enhancing interventions among older adults to increase their motivation for physical activity participation and improve their health.</p>