A considerable number of studies have investigated the relationship between part-time faculty employment and student academic achievement, such as credential completion. However, most studies used cross-sectional data, making it difficult to properly assess the changes in this relationship. In this study, we drew longitudinal data from IPEDS, and linear and quadratic growth models to understand the dynamic relationship between part-time faculty and graduation rates at public two-year colleges. Rigorous analysis results based on growth models and imputed datasets suggested part-time faculty employment is negatively associated with student graduation rates at public community colleges. This research finding might have important implications for resource allocation relevant to faculty employment, institutional excellence, and academic achievement at community colleges.