The role of social support in the lives of higher education students has been considered. However, the relationship of this factor with academic enthusiasm has not been examined. The present study aimed to study the relationship between social support and academic enthusiasm of undergraduate students at Islamic Azad University, Chalous Branch. This study was conducted with a quantitative approach and a descriptive-correlational method. For this purpose, two questionnaires of perceived social support (Zimet et al., 1988) and academic enthusiasm (Fredricks et al., 2004) were distributed among a sample of 511 undergraduate students who were selected by simple random method. The research data were analyzed using Pearson correlation and independent samples t-test. The results indicated that there is a positive and significant relationship between perceived social support and academic enthusiasm of students. It was also found that gender does not make any difference in the perception of social support and its relationship with academic enthusiasm. The results indicate that it is necessary to create a constructive and dynamic atmosphere in the university in a way that improves the level of social support