The evidence for improved patient outcomes following acute hospital reconfiguration is limited. We assessed the impact of the reconfiguration of acute services within a hospital group in terms of the number and clinical management of self-harm presentations. The study was conducted across the three Mid-Western regional hospitals in Ireland during 2004-2014. Reconfiguration in April 2009 involved two hospitals reducing the operation of their emergency departments (EDs) from 24 to 12h. We used Poisson regression analysis of data from the National Self-Harm Registry Ireland to assess change in the hospital burden and clinical management of self-harm associated with the reconfiguration. We observed that the cumulative decrease in self-harm presentations at the two reconfigured hospitals was of a similar magnitude to the increase observed at the larger hospital. Despite this large increase in presentations, there was only a small increase in admissions. Reconfiguration of hospital services was also associated with changes in the provision of assessments for self-harm patients. There is evidence to suggest that acute hospital reconfiguration of hospital services impacts on patterns of patient flow. Findings have implications for those implementing reconfiguration of acute services.