When to commence renal replacement therapy (RRT) in the critically ill remains an unresolved issue. The study by Thakar and colleagues sheds some light on current practice through an international survey, demonstrating physicians' inclination to start RRT earlier when the severity of disease is higher. However, Clec'h and co-workers investigated the effect of RRT on hospital survival by performing a propensity analysis on the large multicentre French OUTCOMEREA database. They demonstrate that RRT does not confer survival benefit, with a delay in initiation being proposed as a contributing factor.