Female university graduates tend to have less career success than their male counterparts. Career optimism is considered a crucial predictor of future career success, but little is known about predictors of career optimism. Based on Social Cognitive Career Theory (SCCT), we hypothesised that both perceived lecturer support and perceived career barriers impact career optimism via students' self-efficacy, and differentiated the model along gender lines using a subgroup path analysis. Two hundred and thirty-two undergraduate psychology students from German universities answered an online questionnaire. Results revealed that the expected indirect effect of perceived lecturer support and perceived career barriers on career optimism via self-efficacy was only identifiable in women. For men, we found a direct connection between perceived lecturer support and career optimism, as well as that an increase in perceived career barriers reduced males' self-efficacy. We were unable to identify any sex differences in career optimism.