Poor synchrony between the delivery of mechanical breaths, the neural respiratory timing, and needs of patients is relatively frequent under mechanical ventilation in the intensive care unit. This review summarizes the current knowledge on the different types of dyssynchrony described to date, their mechanism, consequences, and potential management. There is still a long way to get to a comprehensive knowledge and uncertainties remain. Ongoing research and development of monitoring tools are urgently needed to allow a better appraisal of this area in a near future.