This article describes the development and validation of the Attitudes toward Physical Activity Scale (APAS) to measure the attitudes, beliefs, and self-efficacy toward physical activity by children at the primary school level. The framework included: physical fitness, self-efficacy, personal best goal orientation in physical activity, interest in physical activity, importance of physical activity, benefits of physical activity, contributions of video exercise to learning in school subjects, contributions of video exercise to learning about health and environmental support. The sample comprised of 630 school students between grades 1 and 7 from five countries, namely Lithuania (29%), Poland (26%), Serbia (19%), Singapore (16%) and Zimbabwe (11%). Rasch analysis found empirical evidence in support of measurement validity of the APAS in terms of Rasch item reliabilities, unidimensionality, effectiveness of response categories, and absence of gender differential item functioning (DIF). The validation of the APAS according to the Rasch model meant that a dependable tool was established for gauging programme effectiveness of intervention programs on physical activity of primary school children in classroom settings at various geographical locations globally.