In this field study we examined both positive and negative developmental feedback given in managerial assessment centers in relation to employees’ self-efficacy for their ability to improve their relevant skills assessed in the centers, the extent to which they sought subsequent feedback from others at work, and the career outcome of being promoted to a higher level position within the organization. We found that feedback was related to self-efficacy for improvement which was in turn positively related to feedback seeking, which was positively linked to the career outcome of promotion (e.g., feedback leads to self-efficacy for improvement leads to feedback seeking leads to promotion). In addition, we tested boundary variables for the effects of feedback in this model. Both social support for development and implicit theory of ability moderated the effects of negative feedback on self-efficacy. Having more support and believing that abilities can be improved buffered the detrimental impact of negative feedback on self-efficacy. We discuss implications for theory, future research and practical implications drawing upon literature on assessment centers, feedback and feedback seeking, employee development and career success.