Teachers' emotional states such as optimism and commitment have long been approved influential in second/foreign language education. Although many correlational investigations have been conducted on teacher optimism and commitment, their interaction and kinship with teachers' work engagement have been largely ignored in the literature. Considering this situation, the present mini-review aims to present the theoretical underpinnings, definitions, dimensions, and conceptualizations of these three important variables taken from positive psychology. Moreover, the present review can offer a number of practical implications for EFL teachers, teacher educators, program designers, school principals, and L2 researchers, and raise their awareness of the impact of inner emotions on teachers' academic performance. Finally, research gaps and future directions are provided for eager researchers to run similar and complementary studies in EFL contexts.