An analysis was made of admission rates and patients hospitalized for status asthmaticus at the Children's Hospital of Los Angeles. Despite reports of increasing morbidity and mortality due to status asthmaticus, no significant trend in the admission rate was noted. However, seasonal increases of asthma admissions did occur (October and November), but the increases could not be fully correlated with any environmental factors. In a study of 142 patients, 41 (31%) of the 131 patients who had roentgenograms showed evidence of pneumonitis, suggesting infection as an important factor in status asthmaticus. Acidosis, hypoxia, and hypercapnia result from severe asthma, and frequent clinical and laboratory monitoring of the condition of asthma patients for these serious complications is essential. In addition to the customary treatment of asthma, these abnormalities may be combated by assisted ventilation (intermittent positive pressure breathing by mask or endotracheal tube), muscle relaxants, and alkalizing agents (sodium bicarbonate or tromethamine).