The present study aims to examine whether social adjustment mediates the relationship between psychological wellbeing, and achievement motivation among Arab postgraduate students in malaysia. The participants in this study included 210 Arab postgraduate students in Malaysia. Data were collected using the Grera's Achievement Motivation test ( 2022), Ryff's psychological wellbeing test (1989), and Social adjustment test . Pearson correlation coefficient test and Structural equation modeling using AMOS 23 were used to analyze the data. The results indicated that there were significant relationships between psychological wellbeing, and achievement motivation among Arab postgraduate students in Malaysia. The study findings indicated that social adjustment mediated the relationship between psychological well-being (environmental mastery, autonomy, self-acceptance, positive relations with others, personal growth, and purpose in life) and achievement motivation (Perseverance, Ambition, Goal setting, and Endurance) among postgraduate students in Malaysia.