In 2010, approximately 400,000 tons of titanium dioxide (TiO2) was produced, used and imported in Korea. TiO2 is mainly used as a pigment in paints and paint additives and as a white colorant in foods, cosmetics, drugs, sunscreen, textiles, and toothpaste. To control risks and manage the health and safety concerns of TiO2, the potential risk assessment of TiO2 in humans was investigated in this article. All available reliable studies that investigated TiO2 toxicity were collected by searching the literature for relevant papers. For filling the data gap, the reproductive and developmental toxicity of TiO2 was evaluated using rats. The particle size of TiO2 assessed in this report was >100 nm (except nano-sized TiO2). In repeated inhalation toxicity test, the lung lymph node burdens of TiO2 increased in a concentration-dependent manner and inflammation was noted in bronchoalveolar lavage cells. The tumors observed in rats are thought to be secondary to particle overload in inhalation carcinogenicity studies. There was no indication of any reproductive toxicity in parent animals or developmental toxicity in pups. This study indicated that TiO2 possesses properties that have potential harmful impact on human health due to repeated dose toxicity and carcinogenicity via inhalation.