Patient and Observer Scar Assessment Scale Version 3.0 (POSAS 3.0) is a robust instrument for scar evaluation. Currently, no validated POSAS 3.0 in the Malay language is available. This study aimed to translate, culturally adapt, and psychometrically evaluate POSAS 3.0 for Malay-speaking populations in Malaysia. Malaysian patients were recruited between 31 October 2023, to 31 December 2024. Translation was conducted using a forward and backward translation approach. Reliability was assessed using internal consistency (Cronbach's alpha) and test–retest. Face validity was addressed with 10 patients, and content validity was evaluated by four clinical specialists. Content validity was evaluated using the item-content validity index (I-CVI) and content validity ratio (CVR). Construct validity was assessed using exploratory factor analysis (EFA). Seventy-eight participants with facial (n = 39, 50.0%) and non-facial (n = 39, 50.0%) soft tissue scars were recruited for the EFA. The Malay POSAS-O demonstrated acceptable internal consistency (α = 0.75) and excellent inter-rater reliability, with item-level intraclass correlation coefficient (ICCs) ranging from 0.91 to 1.00 and total score ICC of 0.99. Agreement for categorical scar severity ratings was almost perfect (κ = 0.89). The Malay POSAS-P showed excellent internal consistency (α = 0.89), and test–retest reliability for the total score was good to excellent (ICC = 0.89). Intermittent symptom items (painful, shooting, burning and fragile) exhibited lower stability, reflecting natural symptom variability. Content validity was excellent, with all items achieving I-CVI and CVR values of 1.00. EFA supported construct validity, with adequate Kaiser-Meyer-Olkin (KMO) values (POSAS-O: 0.88; POSAS-P: 0.85), significant Bartlett's tests, strong communalities and factor loadings. The cumulative variance explained was 79.05% for POSAS-O and 68.19% for POSAS-P. The Malay version of the POSAS 3.0 is a reliable, valid, and culturally appropriate instrument for scar assessment. Its strong psychometric properties support its application in clinical practice and research involving Malay-speaking populations.