This research aims to evaluate the psychology properties of the construct validity for the Critical Thinking Disposition (CTD) instrument. The CTD instrument consists of 39 Likert-type items measuring seven dispositions, namely analyticity, open-mind, truth-seeking, systematicity, self-confidence inquisitiveness and maturity. The study involves 433 undergraduate students in University Putra Malaysia. The findings showed that the CTD has satisfactory construct validity with seven factors extracted and confirmed by confirmatory factor analyses. Construct validity results are supported with the Cronbach's alpha values which indicates high validity and reliability for the instrument to measure critical thinking dispositions.