Imidacloprid (IMI), a widely used neonicotinoid insecticide, has raised concerns due to its potential neurotoxic effects, particularly during early developmental stages. This study investigated the impact of postnatal IMI exposure on hematological parameters and acetylcholinesterase (AChE) activity in mice. Mice were exposed to various concentrations of IMI (0, 10, 20, and 30 mg/kg/day) for 21 days. The results revealed significant alterations in blood cell counts, including a decrease in red blood cells, hemoglobin, and packed cell volume, as well as an increase in white blood cells and neutrophils. Additionally, IMI exposure led to reduced levels of basophils and lymphocytes. Maternal exposure to IMI resulted in adverse reproductive outcomes, such as miscarriages. Further, the study observed significant changes in AChE activity, suggesting potential neurotoxic effects. These findings highlight the detrimental effects of IMI on the hematological system and neuronal function in mice, emphasizing the need for further research to assess the long-term health implications of IMI exposure.