Purpose <p>Mosquitoes, known as one of the deadliest creatures on the planet, pose significant risks to the health of humans and animals worldwide by transmitting diseases like malaria, dengue, lymphatic filariasis, West Nile fever, and Zika virus. As mosquito-borne diseases continue to pose a significant threat to global public health, the development and enhancement of effective vector control strategies have become increasingly critical. Among the promising approaches is the use of insecticides such as imidacloprid, a systemic neonicotinoid known for its potent insecticidal properties.</p> Methods <p>This study aims to observe the larvicidal and pupicidal activity of Imidacloprid against <i>Culex quinquefasciatus</i> as per the guidelines of World Health Organisation (WHO). The mortality data were analysed for the determination of LC₅₀ and LC₉₀.</p> Results <p>In this study, the LC₅₀ and LC₉₀ values for <i>Cx. quinquefasciatus</i> larvae were determined to be 0.049 mL/L and 0.137 mL/L, while for pupae, the values were 0.264 mL/L and 0.480 mL/L respectively.</p> Conclusion <p>The obtained results signifies the considerable efficacy of Imidacloprid that could be used as a potential mosquitocide.</p>