The purpose of this study was to explore the buffering role of opportunities for professional development within the frame of the indirect relationship between workplace age discrimination (as a job demand) and job performance on a sample of N = 325 Italian teachers. Results of moderated mediation analysis indicated that emotional exhaustion mediates the relationship between workplace age discrimination and impaired job performance. Furthermore, the relationship between workplace age discrimination and performance through the mediation of emotional exhaustion became stronger at lower levels of professional development. Although professional development is recognized as a crucial job resource, this study sheds light on its protective role among teachers dealing with discrimination caused by their age. Fostering of professional development could prevent teachers from feeling emotionally exhausted and, in turn, from the occurrence of impaired performance.