The aim of this study was to investigate the effect of intravenous lipid emulsion (20% lipid solution) on serum pseudocholinesterase in an toxication model of diazinon. Organophosphate poisoning has a different importance for individuals those admitted to the emergency service due to poisoning. The most commonly used organic phosphorus compounds are diazinon, malathion, and parathion. Intravenous lipid emulsion (ILE) treatment is used as a new treatment method in systemic toxicity cases caused by local anesthetics. Twenty-one male Wistar albino rats, (weighing 180–200 g) were randomly divided into three equal groups. Group I was control, while Group II was diazinon and Group III was diazinon + lipid emulsion treatment. Only 1 ml corn oil was given by gavage to the rats in Group I. A diazinon dose of 335 mg/kg was given by gavage to the rats in Group II. In addition to diazinon, a 20% lipid solution (3 ml/kg) was administered via tail vein to the rats in Group III. At the end of the experimental period, blood samples were taken from animals, and serum pseudocholinesterase levels were measured. When the pseudocholinesterase levels were analyzed, no significant difference was found between diazinon and diazinon + lipid emulsion treatment groups. However, a significant difference was found between control and the others (p < 0.05). In our study, there was no positive effect of lipid treatment detected on serum pseudocholinesterase. Toxication models with lower doses can be designed in future studies.