Background: This research describes the methodology used for the preparation of selenium nanoparticles from Pseudomonas aeruginosa and their administration to lambs for lipid profile checking, administration of selenium nanoparticles as a medication in lambs results in hypolipidemia. Aim: The study aimed to investigate the potential of selenium nanoparticles in improving lipid profiles in lambs. Methods: Healthy lambs (n=10) of similar age and weight were selected for the study. The animals were housed in individual pens with free access to water and a standard diet. The lambs were randomly divided into two groups: the control group (n=5) and the treatment group (n=5). The control group received a standard diet, while the treatment group received the same diet and oral administrated with selenium nanoparticles at 0.1 mg/kg body weight. The administration was carried out daily for a period of 8 weeks. Blood samples were collected from the jugular vein of each lamb at the beginning of the study (baseline) and at the end of the 2 weeks treatment period. The samples were collected in vacutainer tubes and allowed to clot. Serum was separated by centrifugation at 3000 rpm for 10 minutes and stored at -80°C for estimation of lipid Profile (Total Cholesterol, Triglyceride, High-Density Lipoprotein (HDL) and Low-Density Lipoprotein (LDL). The serum samples were used for the estimation of lipid profile levels using an enzymatic colorimetric method. The absorbance was measured at 540 nm using a spectrophotometer. Results: The results showed a significant decrease in serum total cholesterol, triglyceride and VLDL levels after selenium nanoparticle supplementation compared to the control group (p < 0.05), the results indicated a significant increase in serum HDL levels after selenium nanoparticle supplementation compared to the control group (p < 0.05). This indicates that selenium nanoparticle supplementation has a beneficial effect on reducing total cholesterol levels in lambs. Conclusion: The conclusion section will summarize the findings of the study and highlight the potential of selenium nanoparticles in improving lipid profiles in lambs. The implications of the study for animal nutrition and health will be discussed, along with the need for further research in this area.