In the present study, male albino mice were used to estimate the effects of titanium dioxide nanoparticles (TiO2) suspension used in two doses (150, 600 mg/kg) through intraperitoneal route. The results revealed a significant difference (p≤0.05) among the control and experimental groups in all haematological parameters, including a significant increase in White Blood Cell (W.B.C) count, Mean Cell Volume (MCV), Mean Cell Haemoglobin Concentration (MCHC), and Mean Cell Haemoglobin (MCH). Also, the results showed a significant decrease in Red Blood Cell (R.B.C.) count and Haemoglobin (Hb). Biochemical tests included AST and ALT and showed a significant elevation in all exposed groups, while ALP was decreased after fourteen and thirty days of exposure. In the case of kidney function, creatinine was increased in all groups during the experiment, whereas uric acid was increase in many cases and recorded the highest mean value after fourteen days of exposure to the dose of 150mg/kg and after thirty days of exposure to the dose of 600mg/kg. Level of urea was decreased in the fourteen-days and thirty-days treatment groups, while its mean values after using the two doses did not change significantly after one day. Cholesterol level was decreased after thirty days, recording the lowest mean value at 600mg/kg, whereas the level of HDL was significantly (p≤0.05) decreased and that of LDL significantly increased. The study of bioaccumulation demonstrated that the TiO2 NPs are accumulated mainly in the spleen, followed by the liver and kidneys of mice, respectively. Also, the doses used caused histological alterations such as changes in the congested dilated portal tract, with heavy inflammatory cells infiltration and dilated central venule in the liver, along with glomerular congestion, tubular congestion, atrophy, chronic inflammatory cells infiltration, and dilated tubules with flat atrophied lining epithelium in the kidneys. The histologic alterations observed may represent an indication of different degrees of organ injury due to the toxicity of TiO2 NPs, resulting in an inability to deal with accumulated residues from the metabolic and structural disturbances caused by these nanoparticles.