In this study, two middle-school teachers who participated in a professional development program utilizing the transformative professional development (TPD) model are followed as they embarked upon becoming culturally relevant science teachers of Hispanic students. Using Ladson-Billings (1994) theory of culturally relevant pedagogy, teacher interviews, focus groups, journals, and field notes are examined to reveal aspects of culturally relevant pedagogy that the participants translate into their daily science instructional practice in this longitudinal case study. Findings revealed TPD enabled participants to transform their practice to focus on culturally relevant science pedagogy resulting in a more effective instructional environment for their Hispanic students. Implications for further research on professional development and other supports for teachers integrating culturally relevant pedagogy are discussed. (Contains 1 figure.)