Background: The effects of work hours/overtime on nurse and patient outcomes and specific components of work hours (per shift and per week) and overtime on these effects have not been systematically examined. Purpose: The purpose of this review was to systematically evaluate the effect of nurse overtime and long work hours on nurse and patient outcomes. Methods: An online search of six electronic bibliographic databases was conducted for research published from 2000 to 2013. Discussion: Twenty-one nurse outcome measures and 19 patient outcome measures were found in relationships with work hours and overtime. A total of 67 relationships to nurse outcomes and 41 relationships to patient outcomes were examined. Conclusions: The findings of this review suggested that evidence supporting positive relationships between working long hours and adverse outcomes to the nurses is strong. However, to make a conclusion of the positive relationship between long work hours and adverse patient outcomes, more evidence is needed.