Introduction: The Patient Activation Measure (PAM) is one of the most extensively used, widely translated, and tested instruments worldwide in measuring patient activation levels in self-management. This study aimed to determine the validity and reliability of the PAM-13 Malay version among patients with Metabolic Syndrome (MetS) attending a primary care clinic.Methods: This work is a cross-sectional validation study among patients with MetS attending a university primary care clinic in Selangor. The PAM-13 Malay version underwent a validation process and field testing. Psychometric properties were examined using principal component analysis (PCA) with varimax rotation, scree plot, Monte Carlo simulation, internal consistency, and test-retest reliability analyses. Results: The content of the PAM-13 Malay version and the original version were conceptually equivalent. The questionnaire was refined after face validation by 10 patients with MetS. The refined version was then field-tested among 130 participants (response rate 89.7%). The Kaiser–Meyer– Olkin test was 0.767, and Bartlett’s test of sphericity was ≤0.001, indicating sampling adequacy. Two factors were identified and labeled as (1) Passive and Building Knowledge, and (2) Taking Action and Maintaining Behavior. These labels were chosen as they were conceptually consistent with the items representing the levels of activation in PAM-13. The validated PAM-13 Malay version consisted of 13 items, framed into two domains. The overall Cronbach’s α was 0.79, and the intraclass correlation coefficient was 0.45. Conclusions: The PAM-13 Malay version is valid, reliable, and fairly stable over time. This questionnaire can be used to evaluate the levels of activation among patients with MetS in primary care in Malaysia.