Purpose: This paper aims to provide insight into the strategies used by leaders of graduate school preparation programs for science, technology, engineering and mathematics (STEM) to recruit and retain graduate students of color within STEM fields. Design/methodology/approach: This paper is a qualitative multiple-case study using a snowball sample and semi-structured interview protocol. Twenty interviews were conducted. Findings: Graduate program leaders use particular strategies to increase diversity and inclusion within graduate STEM education, and these strategies are strongly influenced by their institutional context. The most common strategies include collaboration, mapping the political terrain, evaluation, mediation, persistence, persuasion, networking in and outside of the institution, strategic planning, bargaining and negotiation, reaching out to the greater campus, and coalition building and developing allies. Research limitations/implications: All of the institutions in this study were public research institutions. Further inquiry is needed on more diverse types of institutions. Practical implications: The results of this study can be used by institutional and STEM program leaders who wish to increase diversity and inclusion. Social implications: This research study raises awareness about an under-studied group of leaders, as well as the importance of considering context when developing strategic plans for increasing diversity and inclusion for STEM. Originality/value: This study is unique because while graduate school preparation programs have become an important strategy for addressing diversity in STEM fields, research on these programs usually focuses only on student outcomes. This study provides rare insight into what is required to implement, sustain and expand these kind of diversity programs.