This paper reports the findings of a study of the impact of the transformative professional development (TPD) model on student achievement on state-mandated assessments of science in elementary school. Two schools (one intervention and one control) participated in the case study where teachers from one school received the TPD intervention across a 2-year period while teachers at the other school received no program and continued business as usual. The TPD program includes a focus on the core conceptual framework for effective professional development (Desimone in "Educ Res" 38:181-199, 2009) as well as an emphasis on culturally relevant pedagogy (CRP) and other effective science instructional strategies. Findings revealed that participation in TPD had a significant impact on student achievement for Burns Elementary with the percentage of proficient students growing from 25% at baseline to 67% at the end of the 2-year program, while the comparison school did not experience similar growth. Implications for future research and implementation of professional development programs to meet the needs of teachers in the realm of CRP in science are discussed.