Objectives: Clinical studies in kidney transplantation are susceptible to early discontinuation and non-publication, contributing to research waste and limiting evidence generation. This study aimed to characterize registered clinical studies in kidney transplantation and identify factors associated with trial discontinuation and non-dissemination. Methods: We searched ClinicalTrials.gov for all clinical studies related to kidney transplantation up to February 2026. Data on enrollment size, study type, and funding source were extracted and analyzed using binomial logistic regression. Results: Among 1,842 eligible clinical studies, 1,505 (81.7%) were completed and 337 (18.3%) were discontinued. Studies enrolling fewer than 100 participants had significantly higher odds of discontinuation (OR = 0.17, 95% CI 0.11–0.26; P < 0.001). Trial discontinuation did not differ significantly between industry-funded and non-industry-funded studies (OR = 1.24, 95% CI 0.82–1.86; P = 0.31) nor between single-center and multi-center studies (OR = 1.13, 95% CI 0.80–1.61; P = 0.49). Conclusion: A notable proportion of kidney transplantation clinical studies are discontinued before completion, contributing to research inefficiency and limiting the generation of robust evidence in transplantation medicine. Our analysis suggests that studies with smaller sample sizes are significantly more prone to discontinuation, while funding source and study setting do not appear to significantly influence study completion. These findings emphasize the importance of adequate recruitment planning and realistic study design to enhance trial feasibility and completion rates. Strengthening these aspects may help reduce research waste and improve the overall impact of kidney transplantation clinical research.