This study examines the development of preservice secondary science teachers’ understanding about equitable assessments (EA) as a result of instruction during a methods course and their subsequent use of EA, while planning a science unit without prompting. The author concludes that preservice teachers gained in the following domains of knowledge introduced earlier: (1) knowledge and beliefs about diverse learners, (2) knowledge and beliefs about EA strategies, and (3) skills in modifying assessments for English language learners. They displayed relevant knowledge, but did not enact it as well when it came to planning units.