The relationship between sick building syndrome (SBS) symptoms and microenvironmental parameters in buildings was investigated. The study group consisted of 137 persons, 89 females, working in offices in five buildings in Pittsburgh, Pennsylvania. The subjects completed a linear analog questionnaire to obtain information on demographic characteristics, occurrence and intensity of SBS symptoms such as eye, nose, and throat irritation, chest tightness, headache, difficulty concentrating, skin problems, irritability, and fatigue, work activities, smoking, and personal characteristics such as wearing contact lenses and glasses, and type of clothing. Microenvironmental parameters such as temperature, humidity, noise, carbon-monoxide (630080), carbon-dioxide (124389), volatile organic compounds (VOCs), respirable dust, light intensity, and air speed were measured simultaneously. Heat stress was assessed from the temperature, humidity, and air speed data. Attempts were made to correlate reported symptoms with the microenvironmental data and questionnaire findings by analysis of variance and regression techniques. All five buildings had central heating and air conditioning systems. Eye, nose, and throat irritation and headache, difficulty in concentrating, irritability, and fatigue, which were regarded as mucous membrane and central nervous system symptoms, respectively, were significantly associated with VOC and carbon-dioxide concentrations, layers of clothing, and lighting intensity. Both symptom groups were strongly associated with smoking density. Chest tightness and difficulty concentrating were weakly associated with carbon-dioxide concentration. Multivariate regression analysis showed that age, educational background, sex, and smoking density were not significantly related to symptoms. VOC concentration and lighting intensity were stable and consistent predictors of symptoms. The authors suggest that symptoms associated with indoor air quality may result from specific pollutants present in offices not from inadequate air handling systems. Each type of pollutant may require different remediation strategies.