•Less than 50% of patients completed their intramuscular vaccine regimen despite vaccine availability.•Low completion rates were observed among high-risk individuals and patients living in high rabies burden provinces.•Patients who received eRIG had lower odds of completing their vaccine regimen compared to those patients that did not. Adhering to post-exposure prophylaxis (PEP): wound treatment, vaccine, and rabies immunoglobulin (RIG) is a crucial step in preventing rabies mortality. When PEP is widely available, a lack of adherence to the recommended treatment guidelines can also lead to death. Our objective was to understand characteristics associated with adherence to the vaccine regimen and RIG in Vietnam. We obtained individual-level data on PEP adherence from registries at 10 sites located in five provinces. From these registries, we extracted epidemiologic characteristics of patients including the timing of PEP initiation and completion. We used descriptive analyses and logistic regression to examine patient characteristics associated with initiation and completion of RIG and vaccine. Based on reported rabies mortality, the government defined provincial rabies burden as medium-burden (<5 and >2 deaths) and high-burden (≥5 deaths). During 2014–2016, 15,646 patients received PEP in our study. Among 14,296 vaccinated patients, only 41.4% (5847) completed their five-dose intramuscular (IM) injections and 81.6% (133) of patients completed their eight-dose intradermal (ID) injections. Approximately 26% of patients received RIG. Patient characteristics associated with vaccine completion were females (44%), <15 years of age (44%), category 1 exposure (68%, bite location on leg (46%), bite from bat (56%), bite from a healthy animal (45%), high-burden province (86%), and district preventive center (49%). Disparities were revealed among provinces, with high-burden provinces having highest (86%) and lowest (7%) vaccine completion rates. Vietnam has made tremendous progress towards reducing the burden of rabies. However, despite the wide availability of PEP, we found relatively low rates of vaccine completion. Our findings suggest provider training and patient education is needed to ensure appropriate treatment is completed. Moreover, our data suggest changes to information reported through the national surveillance system for monitoring good clinical practice for rabies prevention and control.