A mixed methods design was applied to evaluate the application of the Perceived Locus of Causality scale (PLOC) to preadolescent samples in physical education settings. Subsequent to minor item adaptations to accommodate the assessment of younger samples, qualitative pilot tests were performed (N = 15). Children's reports indicated the need for further revisions to the items, resulting in the Children's PLOC (C-PLOC). In a second study involving a larger sample of 9-12 year old children (N = 429), the questionnaire was evaluated using quantitative methods. The five factor structure hypothesized based on self-determination theory was confirmed. Discriminant validity and reliability of the subscales was largely supported, but require confirmation in future research. Age was not found to be significantly related to children's motivational styles. Taken together, initial results provide support for the suitability of the C-PLOC for the assessment of motivation in 9-12 year old children in physical education.