Abstract : Visceral leishmaniasis consider a great health problem in Iraq, the traditional antileishmanial therapies are toxic and most are costly. For this reason, new approaches in the treatment of leishmaniasis are requested, zirconia nanoparticles ZrO2NPs, is a nano-sized and hollow colloidal metal oxide, it was recorded as anticancer agent, the approach was to prepare 17.4 μg/ml of ZrO2NPs by pulsed laser ablation. These nanoparticles are described to confirm the shape, size and other physical properties of the crystal using the following techniques: X-Ray Diffraction (XRD), results were indicated diffraction peaks at (28.2°, 31.5°, 38.5°, 50°, and 59.8°) were correspond to the (111, 111, 120,022 and 131), respectively. The Transmission Electron Microscopy (TEM) shown confirms the formation of nanostructures with granular size by 50 pulses of laser. The effect of ZrO2NPs on the parasite was tested in vivo by observation the levels of liver enzyme (aspartate aminotransferase AST, alanine aminotransferase ALT and cholesterol CL) in serum of infected mice and dosed with ZrO2NPs (0.1 ml / day) and comparing with control positive group after 7,14 and 21 days of dosed. The results showed that the level of AST in treated mice with ZrO2NPs significantly decreased at second and third week (49.17±0.70, 46.83±0.70 U/L) respectively, compared with the positive group was (61.83±1.33, 84.00 ±2.63U/L), there is significantly decrease at second and third week in level of ALT (50.00±0.58, 45.33 ±0.80) respectively, compared with the positive group (66.33±0.92, 79.67±2.22 U/L), respectively. As well as the results showed a significant increase in the cholesterol level within second and third weeks when mice were dosed with ZrO2NPs (164.83 ±1.70, 170.33 ±1.31 mg/dl) compared with positive group (139.83±1.35, 98.33±4.62 mg/dl).