Many doctoral students fail to finish their degrees, often stopping out at the dissertation stage. This article reviews successful dissertation mentoring practices, focusing on mentors' roles in aiding the completion of these degrees. Drawing on Kram's mentoring support framework--psychosocial and career/instrumental factors--the review employs qualitative meta-synthesis to integrate qualitative research findings. The synthesis reveals that successful dissertation mentorship hinges on mentors' expertise, passion, care, and representation. Key findings underscore the value of trust-building, setting high expectations, nurturing professional relationships, mutual respect, and encouragement. Moreover, career and instrumental support are crucial, encompassing accessibility, guidance, coaching, resource provisioning, modeling, feedback, and advocacy. The study highlights the alignment of effective dissertation mentorship with Kram's framework, spanning psychosocial and career/instrumental dimensions. It underscores the significance of tailored mentorship in facilitating doctoral students' successful dissertation completion and overall academic achievement.