Continuous positive airway pressure (CPAP) is the leading treatment for obstructive sleep apnoea (OSA), a prevalent disorder of breathing in sleep strongly associated with obesity. OSA has serious adverse health, social and community effects arising from disturbed breathing, loud snoring, poor quality sleep and cardiovascular sequelae. When used appropriately, CPAP treatment is highly effective in normalising breathing and sleep, improving symptoms and lowering adverse event risk. However, patients do not necessarily accept, tolerate or comply with treatment, with many factors influencing CPAP uptake and longer term use. Although knowledge to address challenges affecting CPAP adherence and CPAP mask and machine technologies continue to improve incrementally, optimising CPAP treatment adherence is an ongoing challenge in sleep medicine.