This exploratory study determined PhD completions at a research-intensive university in New Zealand and considered factors affecting PhD completions. Completion data were calculated for PhD cohorts at the University of Otago from 2000 to 2012 (n = 2770) and survival models determined whether gender, enrolment status, age at admission, citizenship, scholarship status and academic field influenced completion. The impact of the doctoral programme and the research environment was also considered. Across all cohorts, 83% submitted their thesis for examination (17% withdrawal). The median submission time was 3.4 years for full-timers, with a median completion time (to award of degree) of 4.1 years. Survival modelling showed that completion can be enhanced by having mainly full-time candidates, but also allowing periods of part-time enrolment near submission, recruiting a large international cohort, and providing three year scholarships. Health science candidates had the highest submission percentages, while commerce candidates submitted in the fastest times. There were only minor or negligible effects of gender and age at admission. Other factors contributing to high submission rates included recruiting quality candidates, close monitoring during candidature, provision of research training, a vibrant research culture, a personal performance coach, high-quality supervision and funding incentives for candidates who submit in under four years.