Author summary Why was this study done? Clinical trials are the foundation of evidence-based medicine and should follow established guidelines for transparency: Their results should be available, findable, and accessible regardless of the outcome. Previous studies have shown that many clinical trials fall short of transparency guidelines, which distorts the medical evidence base, creates research waste, and undermines medical decision-making. University Medical Centers (UMCs) play an important role in increasing clinical trial transparency but are often unaware of their performance on these practices, making it difficult to drive improvement. What did the researchers do and find? We developed a pipeline to evaluate clinical trials across several established practices for clinical trial transparency and applied it in a cohort of 2,895 clinical trials led by German UMCs. We found that while some practices are gaining adherence (e.g., prospective registration in ClinicalTrials.gov i