Boron is a naturally occurring metalloid, widely distributed in nature. Boron is not essential for humans. People are exposed to boron mainly via drinking water, including bottled water, and food, but also occupationally. Little is known about potential health effects of boron exposure. In experimental animal studies, boron exposure has been shown to cause testicular lesions and affect early-life development, including bone malformations and lower birth weight. Studies on workers with occupational exposure to boron have, however, not revealed evidence for impaired fertility. On the other hand, our recent studies in the Andean part of northern Argentina, with elevated boron concentration in the drinking water in some villages, showed that serum boron concentrations above 80 µg/L during pregnancy were inversely associated with length and weight at birth. A follow-up study in the same study area showed that also infant boron exposure could be detrimental for the infant growth and that boys seem to be more susceptible than girls. In this presentation, a critical review of the scientific evidence available concerning occupational and environmental boron exposure and health effects will be presented and discussed.