Purpose: The paper aims to follow social exchange theory and group social capital theory, to predict positive relationships between (informal) mentoring and various support resources for two types of performance (i.e. perceptions of individual and team performance). Design/methodology/approach: The associations of individual-level mentoring and team-level support with job performance were examined in a cross-level field study using data from 480 teachers working in 64 interdisciplinary teams. Findings: Multilevel analyses showed that after controlling for having a mentor, those teachers with more team-level support resources scored higher on self-reported job performance and perception of team performance. In line with expectations, the association between mentoring and individual job performance was stronger for teachers scoring high on team-level support (i.e. support from informal networks and support from team orientation). One basic assumption of the present study was a positive relationship between individual-level mentoring and job performance. Surprisingly, such a direct relationship between mentoring and job performance was not found: only the moderating relationships mentoring appeared to be associated with job performance. Research limitations/implications: In the present study, only a global measure of mentoring was used (only yes or no) and this measure did not differentiate between mentoring functions and/or outcomes. However, future research could benefit from including more differentiated measures of mentoring to be able to predict more precisely how various support measures are linked with job performance. Originality/value: Typical dependent measures in mentoring research include career success, career satisfaction, income, promotions, etc. However, with increasing emphasis on working in teams, there is a need to expand the criterion domain and to include a team level measure. Therefore, a distinction was made between the perception of individual job performance of the respondents and the perception of team performance of the team where the respondent is working in. (Contains 2 tables, 2 figures and 1 note.)