The positive role of reflective teaching and well-being as means of fostering teaching quality has mainly remained at the level of speculation and there is little empirical evidence to illustrate their impact on enhancing professional development. To fill this existing gap, this study examines the contribution of reflection and psychological well-being as predictors of professional development. Adopting a mixed-methods approach, 350 English language teachers were selected randomly and participated in a survey. Following that, six teachers through purposeful sampling participated in a focus group interview to investigate the relationship among the aforementioned variables. The correlational analysis confirmed the positive relationship among these three constructs and a structural equation modeling indicated that both reflection and well-being significantly predicted professional development; however, well-being was a stronger predictor compared to reflection. The qualitative analysis of data revealed four main themes contributing to professional development among teachers. The pedagogical implications are also elaborated and discussed.