Doctoral completion rates are of concern to human resources development policy of universities as they endeavour to enhance the academic excellence of their university. The purpose of this study is to investigate the factors influencing doctoral completion success rates amongst staff of a public university in Thailand. The categories of the binary outcome variable, doctoral achievement are successful and unsuccessful or incomplete. The determinant variables include gender, age at the commencement of the doctoral degree, country group of doctoral study and the major or field of doctoral study. Data were obtained from the university's database. Logistic regression was employed to model the effects of multiple determinants on doctorate achievement. The results showed that gender, country of study and field of doctoral study are significant factors leading to successful doctoral completion but age at the commencement of a doctoral degree was not a significant factor. Identification of such factors could be done for other universities so that they can modify their human resources development strategies to support candidates who may be at risk of failure.