Objective: To determine personal and workplace factors associated with quad bike loss of control events (LCEs) on New Zealand farms. Methods: Rural community databases were used to sample 130 farmers and farm employees (workers). Fieldwork and survey investigated for prevalence of LCEs; farm type; farm terrain; personal measures; and vehicle driving exposures. Results: Seventy nine workers (61%) described a total of 200 LCEs. Increased driver height, increased body mass, non-flat farm terrain, increased driving speed and distance, and greater whole body vibration exposure were significantly associated with LCEs. Conclusions: Taller and heavier drivers of quad bikes should be particularly vigilant for risk of an LCE. Vehicle speed, distance driven and choice of driving routes over difficult terrain are potentially modifiable factors which have behavioural components and should be considered as management strategies for reducing risk of on-farm quad bike LCEs. Relevance to industry: Quad bike accidents are a considerable problem in agriculture. This research has identified a number of physical and driving factors that should be considered in the management strategies for reducing risk of on-farm quad bike accidents.