This study evaluated potential subacute effects associated with Dimethylcyclosiloxane Fluid. Five groups of 8 female and 8 male Charles River CD Sprague Dawley rats were administered 25, 100, 400, or 1600 mg/kg/day of the test substance via oral gavage 5 days a week for 2 weeks. One group was given 4 ml/kg of a 0.5% suspension of Methocel A4M and distilled water and served as the vehicle control. The animals were observed daily on week days for signs of toxicity, general appearance, behavioral abnormalities, signs of local or systemic toxicity, and mortality. On weekends the animals were observed for mortality. Body weights were recorded prior to the sixth dose for recalculation of the dosages, and at necropsy. Gross necropsy was performed on all animals. No significant signs of toxicity or behavioral changes were seen in any of the animals. Group mean terminal body weights were statistically significantly lower in the high dose group male and females when compared to the controls. Male and female animals in the 400 and 1600 mg/kg/day groups showed statistically significant increases in group mean relative liver weights. Female group mean liver weights were also significantly increased in the 100 mg/kg/day group. Absolute liver weights were significantly increased in the 400 and 1600 mg/kg/day females. A significant trend was observed through the lowest male and female dose group. Doses of 100, 400, and 1600 mg/kg/day of Dimethylcyclosiloxane for 14 days produced significant treatment-related increase in the liver weights of rats.