© 2015 Sports Medicine Australia.Objectives: To examine the potential relationship between sleep duration and efficiency and injury incidence in elite Australian footballers. Design: Prospective cohort study. Methods: Australian footballers (n = 22) from one AFL club were studied across the 2013 competitive season. In each week sleep duration and efficiency were recorded via actigraphy for 5 nights (the 3 nights preceding a game, the night of the game and the night after the game). Injury incidence was monitored and matched with sleep data: n = 9 players suffered an injury that caused them to miss a game. Sleep in the week of the injury (T2) was compared to the average of the previous 2 weeks (T1). A two-way repeated measures ANOVA was used to determine any effect of sleep duration and efficiency on injury. Significance was accepted at p <0.05. Results: Injury incidence was not significantly affected by sleep duration, sleep efficiency or a combination of these factors. Analysis of individual nights for T2 versus T1 also showed no differences in sleep quality or efficiency. However, a main effect for time was found for sleep duration and efficiency, with these being slightly, but significantly greater (p <0.05) at T2 (437 ± 61 min and 82 ± 7%) than T1 (414 ± 64 min and 79 ± 7%). Conclusions: No significant effect of sleep duration and efficiency on injury occurrence was found in elite Australian footballers.