<p>Mosquitoes contribute significantly to the spread of infectious diseases by hosting agents like parasites and pathogens, which cause serious health impacts for millions of people each year. This study aimed to evaluate the efficacy of <i>Anacardium occidentale</i> leaf extracts in mosquito control while promoting environmentally friendly strategies for vector eradication. The insecticidal effects of methanol, ethanol, hexane, and acetone extracts of <i>Anacardium occidentale</i> were systematically tested against fourth instar <i>Aedes aegypti</i> larvae. Among the individual extracts, acetone demonstrated the highest potency, with an LC₅₀ value of 795.480&#xa0;ppm. Hexane had an LC₅₀ of 1145.543&#xa0;ppm, ethanol 1353.710&#xa0;ppm, while methanol was the least effective, with an LC₅₀ of 3483.042&#xa0;ppm. Interestingly, the combined synergistic action of all extracts further enhanced their insecticidal activity. Phytochemical screening of <i>Anacardium occidentale</i> extracts revealed a rich composition of bioactive compounds, including alkaloids, flavonoids, tannins, and saponins, which significantly contributed to their biological effects. Additionally, GC–MS analysis identified essential bioactive compounds such as fatty acids, heterocyclic compounds, and esters, which play a key role in the plant’s larvicidal effectiveness. Due to its insecticidal potential, <i>Anacardium occidentale</i> offers an environmentally friendly and cost-effective solution for limiting the transmission of specific mosquito-borne illnesses. These findings suggest that the insecticidal potential of <i>Anacardium occidentale</i> leaf extracts—validated through GC–MS analysis—could be harnessed in synergistic formulations or scaled for future eco-friendly vector control strategies.</p>