Fifty years ago, in 1932, skeletal fluorosis was discovered as an occupational disease in cryolite workers in Copenhagen, Denmark. Following the initial reports, new cases were identified in other industries, such as the production of aluminum and superphosphate fertilizer. In light cases of fluorosis, the bone changes are often associated with nonspecific joint and muscle pains, but the disease may be entirely asymptomatic. The fluoride-induced osteosclerosis seems to be reversible, but the long-term significance of fluoride accumulation in the body is not known. Family cases of dental fluorosis have been occurred in long-term residents near fluoride-emitting industries, and in hot areas with high, natural fluoride levels in the drinking water. Skeletal fluorosis has only played a minor role in the discussion concerning fluoridation of drinking water, however. Changing and increasing uses of fluorides have led to a renewed interest in this occupational disease.