The respiratory rate is a sensitive and nonspecific indicator of respiratory dysfunction. Establishing a "normal" respiratory rate has mainly been arbitrary. This study evaluated "normal" respiratory rates in 110 emergency department patients. The mean respiratory rate was 20.1 (+/- 4.0). Women had a more rapid respiratory rate 20.9 (+/- 3.9) than men 19.4 (+/- 4.0) (p less than .04). Smokers had a higher respiratory rate 20.5 (+/- 4.0) than nonsmokers 19.3 (+/- 4.0), but this was not statistically significant (P = 0.124). It was also noted that the respiratory rate measured by the nurse was almost always different from that measured by the medical student (P less than 0.0001). Based on a review of the literature concerning what constitutes a "normal" respiratory rate, we conclude that the "normal" respiratory rate may be higher than that suggested in the medical literature.