This paper studies the relationship between proactive personality, social support and self-esteem on career adaptability among postgraduate business students, in a public university in Malaysia. The study used the quantitative approach and online survey questionnaires to collect data from the business doctoral students. Regression analysis was used to determine the relationship between proactive personality, social support and self-esteem with career adaptability among postgraduate students. The study collected from 214 postgraduate students reported that proactive personality and social support are significant in explaining career adaptability while self-esteem was found not significant in explaining career adaptability. This study sheds light on the factors contributing to postgraduate students’ career adaptability. The main challenge lies in adjusting to the work environment, which is influenced by the workplace and the support from employers, especially the Human Resource (HR) teams. HR can develop strategies to help these students better adapt to their new roles, making their transition into the professional world smoother and more successful.