This study explored the effects of community-based service-learning (CBSL), supplemented with discussions and activities about diversity, on the self-efficacy beliefs of preservice elementary teachers regarding equitable science teaching and learning for diverse student groups. The study was conducted with 81 preservice teachers enrolled in four sections of an elementary science methods course over a semester. Employing a mixed-methods research design, data were collected using pretests-posttests with the study sample and semistructured interviews with a subsample. The results support the value of preservice teachers engaging in CBSL experiences, supplemented with discussions and activities about diversity, as a way to improve their self-efficacy beliefs regarding equitable science teaching and learning of "all" students.