This study seeks to examine the impact of alumni connections between the evaluators and evaluatees on the results of peer review ratings for the Korean national R&D project and selection success rate. Specifically, this study analyzed the evaluation results of 8,402 research proposal entries submitted between 2007 and 2011 for the "general researchers support project," all in the Natural Science and Engineering areas and sponsored by the National Research Foundation of Korea. Each proposal entry was evaluated by three evaluators, and approximately 39 percent of the proposals had at least one evaluator from the same university. The results of this study showed that evaluators have a tendency to give relatively high scores to research proposals submitted by the alumni of the same universities as their alma mater. Also, when an evaluator from the same university as an evaluatee was included in the evaluator group, the results of this study showed that the percentage of entry submissions was higher compared to the contrary. Such results show that in the process of peer review–based research proposal evaluations for national R&D projects, alumni connections have significant influence on evaluation results in South Korea.