Firefighter mortality studies that used standardized mortality ratio (SMR) as a summary measure are reviewed and an overview of time-dependent mortality effects for all causes, CAD, cancer, and respiratory deaths is provided. Of 17 studies reporting SMRs for firefighters, three overlapped with larger studies and six did not contain time-dependent data, leaving eight for inclusion. The time effects showed no increased mortality with increasing time employed and time since first employment (latency) for all-cause mortality or any specific cause. There were many causes of death for which firefighters' SMRs were below one through all durations of employment and latency. There was no convincing evidence that employment as a firefighter is associated with increased all-cause, CAD, cancer, or respiratory disease mortality.