Recently, patients who have been exposed indoors to mixed molds, spores, and mycotoxins have reported asthma, airway irritation and bleeding, dizziness, and impaired memory and concentration, all of which suggest the presence of pulmonary and neurobehavioral problems. The author evaluated whether such patients had measurable pulmonary and neurobehavioral impairments by comparing consecutive cases in a series vs. a referent group. Sixty-five consecutive outpatients exposed to mold in their respective homes in Arizona, California, and Texas were compared with 202 community subjects who had no known mold or chemical exposures. Balance, choice reaction time, color discrimination, blink reflex, visual fields, grip, hearing, problem-solving, verbal recall, perceptual motor speed, and memory were measured. Medical histories, mood states, and symptom frequencies were recorded with checklists, and spirometry was used to measure various pulmonary volumes and flows. Neurobehavioral comparisons were made after individual measurements were adjusted for age, educational attainment, and sex. Significant differences between groups were assessed by analysis of variance; a p value of less than 0.05 was used for all statistical tests. The mold-exposed group exhibited decreased function for balance, reaction time, blink-reflex latency, color discrimination, visual fields, and grip, compared with referents. The exposed group's scores were reduced for the following tests: digit-symbol substitution, peg placement, trail making, verbal recall, and picture completion. Twenty-one of 26 functions tested were abnormal. Airway obstructions were found, and vital capacities were reduced. Mood state scores and symptom frequencies were elevated. The author concluded that indoor mold exposures were associated with neurobehavioral and pulmonary impairments that likely resulted from the presence of mycotoxins, such as trichothecenes.