The objectives of this study were to measure the relative strength, significance and contribution of factors associated with rural and remote medical workforce retention. Length of stay data from two Australian GP workforce datasets, the 2008 National Minimum Data Set (4223 GPs) and a subset of the 2008 Medicine in Australia: Balancing Employment and Life dataset (1189 GPs), were separately analysed using multiple linear regression models and the results compared. Length of employment in their current practice location was the outcome measure. Consistent results were obtained across both datasets. The most important factors associated with the retention of rural and remote GPs, after adjusting for GP age, were primary income source, registrar status, hospital work and restrictions on practice location (which are linked to geographic location). Practice ownership was associated with ∼70% higher retention than average, whilst undertaking hospital work in addition to routine general practice was associated with at least 18% higher retention compared with if no hospital work was undertaken. Less important factors included geographic location, procedural skills, annual leave, workload and practice size. Our findings quantify a range of financial and economic, professional and organisational, and geographic factors contributing to the retention of rural GPs. These findings have important implications for future medical workforce policy, providing an empirical evidence base to support the targeting and 'bundling' of retention initiatives in order to optimise the retention of rural GPs.