We build upon the social cognitive career theory model of career self-management (SCCT-CSM) to test the effects of psychological capital constructs (hope, self-efficacy, optimism and resilience) on preparatory and active job search behaviours, mediated by job search goals in a multi-group study of university graduates who undertook work placement learning before graduation and those who did not. Using a two-wave data from 473 university fresh graduates in the one-year national youth service corps (N = 209 who undertook work placement learning before graduation) and (N = 264 who did not undertake work placement learning) in Nigeria, we test an SCCT-CSM-driven model employing structural equation modelling for the multi-group study. The findings revealed positive effects of self-efficacy and optimism on the preparatory and active job search behaviours across both samples but higher effects in the graduates who undertook work placement learning before graduation. Job search goals mediated the effects of self-efficacy and optimism on their preparatory and active job search behaviours in both samples. The serial mediation results show that self-efficacy and optimism indirectly affect the active job search behaviours via job search goals and preparatory job search behaviours. The implications of these results are discussed.