To more effectively reduce the death toll and injuries from future earthquakes researchers need to identify the causes of injury. In this study we investigated causes of injury during the 2010/2011 Canterbury earthquakes. Data on patients injured during the Darfield (4 September 2010) and Christchurch (22 February 2011) earthquakes were sourced from the New Zealand Accident Compensation Corporation. The total injury burden was analysed for demography, context of injury, causes of injury, and injury type. Injury context was classified as direct (immediate shaking causing injuries), action (movement of person causing injuries), and secondary (cause of injury after shaking ceased). Nine categories of injury cause were identified. Three times as many people were injured in the Christchurch earthquake as in the Darfield earthquake (7171 vs 2256). The primary shaking caused approximately two-thirds of the injuries from both quakes. Actions during the main shaking and aftershocks led to many injuries (51.3% Darfield and 19.4% Christchurch).  “Primary direct” caused the highest proportion of injuries during the daytime Christchurch quake (43.6%). This study demonstrated that people’s location and their actions during and after earthquakes influenced their risk of injury. This research will help planners adopt land-use practices that guide growth away from hazard-prone areas, and will help engineers design safer buildings.  Researchers also need to better document the numbers and types of injuries.  This will allow emergency managers to better train residents of earthquake risk areas to take appropriate protective actions and emergency medical personnel to improve their response plans and preparedness.