Potential exposures and health risks of unskilled construction workers (construction laborers) were analyzed. English language articles contained within the databases Toxline, Medline, HSEline, a database maintained by the United Kingdom Health and Safety Executive, and the NIOSHTIC database were searched to characterize the job tasks, exposures, and health risks of construction laborers. Mortality data from California and Washington State which code occupation on their death certificates, mortality data collected from death certificates for 876,731 decedents in 19 states which were supplied to NIOSH, national fatality statistics, cancer registry data, and case reports of specific causes of morbidity were also utilized. The findings were compared with those in a NIOSH job exposure matrix developed from data collected by the National Occupational Exposure Survey. Health risks were evaluated by computing proportionate or standardized mortality ratios or morbidity ratios for various causes. The four most frequent occupational exposures, with at least 100,000 workers being exposed, were diesel fuel combustion products, segmental vibrations, calcium- carbonate (471341), and noise. Approximately 23,000 workers were exposed to lead (7439921) and 14,000 to asbestos (1332214). Clearly elevated risks for mesothelioma, traumatic injuries, acute lead poisoning, musculoskeletal disorders, noise induced hearing loss, and dermatitis could be established. Elevated risks were also found for total mortality, cirrhosis, cerebrovascular disease, chronic obstructive pulmonary disease (COPD), ischemic heart disease (IHD), and leukemia; however, it could not be determined to what extent these were occupationally related. The authors conclude that construction laborers have definite increased risks for mesothelioma, traumatic injury, lead poisoning, musculoskeletal disorders, and dermatitis.