There is interest in admission criteria that predict future success in biomedical graduate school programs, but identifying predictors of PhD attainment is inherently complex. In particular, high noncompletion rates of PhD programs have long been recognized as a major crisis. Here, we present a quantitative analysis of the PhD students enrolled in the Department of Biochemistry and Biophysics at Texas A&M University between 1980 and 2010. The input variables included sex, country of citizenship, undergraduate grade point average (GPA), and Graduate Record Examination (GRE) scores (Verbal and Quantitative Reasoning). Only GPA was a significant predictor of PhD completion based on logistic regression. We also examined associations involving nonbinary measures of success (PhD duration, first author, and total number of publications) among students who completed a PhD. GPA was again associated with the PhD duration. No enrollment variable was strongly associated with publication output. Despite potential limitations, this analysis is the first to suggest an undergraduate GPA association with PhD completion in life sciences. These results from a large state university in a predominantly rural area expand the range of programs from which such analyses have been reported.