We examined the validity of the factor structure and invariance of the Perceived Locus of Causality (PLOC) scale instrument scores across two nations endorsing collectivist (Singapore) and individualist (Great Britain) cultural values. Results indicated that confirmatory factor analytic models of the PLOC exhibited adequate fit according to multiple criteria within each sample and across samples. There was invariance in the item-intercepts across the two cultures. In additioh, the simplex-like pattern of relations among the PLOC constructs was confirmed within cultures and in invariance analyses. Finally, latent factor means analysis revealed that the British participants tended to rate less self-determined forms of motivation lower than and more self-determined forms of motivation higher than the Singaporean participants.