This study examines how and whether the constructs of openness to experience in the work placement learning setting (openness to learning in a new environment, openness to supervisor feedback, and openness to diversity) might influence students’ readiness for school-to-work transition. Also, it builds upon the assumptions of the social cognitive career theory – model of self-career management to examine the mediating effect of self-efficacy in the proposed relationships. Analysis of 543 responses from undergraduate students undertaking work placement learning in 221 Nigerian firms using the structural equation modelling revealed positive effects of the constructs of openness to experience on students’ readiness for school-to-work transition. Also, self-efficacy was a significant mediator in the positive relationships. Our findings make important theoretical and practical contributions by offering highlights into the crucial role of openness to experience in enhancing students’ readiness for school-to-work transition via self-efficacy in the work placement learning setting.