The aim of this study was to investigate the influence of weather conditions on the frequency of acute laryngitis in adults. The medical records of 825 patients with a diagnosis of acute laryngitis obtained over a 5-year period were reviewed. Meteorological data reviewed included the daily values of 13 parameters. The monthly distribution of the disease was assessed. In addition, a detailed 2-part statistical analysis was performed as follows: (i) the relationship between each meteorological parameter and the frequency of the disease was investigated, using contingency tables; and (ii) the 1825-day period was divided into 8 groups characterized by similar weather, using factor and cluster analysis, and the disease frequency in each group was assessed. Our observations were as follows: 1. Meteorological parameters, such as low temperature, low diurnal temperature range, low atmospheric pressure and low mean water vapor pressure, were associated with an increased occurrence of acute laryngitis. 2. Significant changes in maximum temperature or a significant drop in atmospheric pressure, as compared to the previous day's conditions, favored new cases of the disease. 3. The cold period of the year was associated with an almost two-fold increase in the frequency of disease cases, which peaked in March and reaching a minimum during August. 4. The peak frequency of cases was associated with winter weather conditions, which were characterized by high humidity readings. In conclusion, meteorological parameters, and their variation and covariation, are strongly associated with acute laryngitis in adults.