Respiratory rate is an early indicator of physiological deterioration and should be recorded with other vital signs in patients who present to emergency departments. This article highlights the importance of recording patients' respiratory rates and describes their place in initial patient assessments. It also reviews findings from an audit of ED patients' notes over a short period to discover whether their respiratory rates had been recorded. These support the results of similar studies in the literature, which show that, despite their importance, respiration rates are documented less often than other vital signs.