Burnout levels among medical residents are considered high. A lack of social support has shown to have a direct effect on emotional exhaustion, and depersonalization, two of the three burnout indicators. In this study, we examined the satisfaction of medical residents with social support (emotional, appreciative and informative) received from supervisors, fellow medical residents, nurses and patients. In addition, the correlation between social support and burnout was studied. Medical residents were significantly more dissatisfied with the emotional, appreciative and informative support received from their supervisors compared with fellow residents and nurses (respectively, 13.4 ± 4.0 vs. 9.9 ± 2.8 and 10.0 ± 2.4; 10.0 ± 2.9 vs. 7.4 ± 2.0 and 7.3 ± 1.8; and 7.2 ± 2.3 vs. 5.4 ± 1.6 and 5.3 ± 1.5; p < .001). Significant independent effects were found on emotional exhaustion: from dissatisfaction with emotional support [Beta = .44, p < .001, total R2 = .25] and dissatisfaction with appreciative support from supervisors [Beta = .30, p < .01, total R2 = .11]. Moreover, dissatisfaction with emotional support from supervisors had an independent significant effect on depersonalization [Beta = .33, p = .001, total R2 = .14]. The best predictor of burnout appeared to be dissatisfaction with emotional support received from supervisors. Our results suggest that intervention programs should not only focus on the medical residents, but also on the supervisors to improve their supportive skills.