At the outset is presented a description of the various aspects of malaria, including life cycle of malaria parasite, epidemiology, pathogenesis, clinical features, diagnosis, complications and treatment with due emphasis on artemisinin-based combination therapy ACT) in chloroquine resistant malaria. The related disease, tropical splenomegaly, following chronic/recurrent malarial infections as an abnormal immunological response, is also described. Next, the chapter dwells on kala-azar (black sickness), which some years back crossed its known geographical boundaries, with due coverage of the new trends in its treatment in the form of amphotericin B and kala-azar vaccine that is around the corner. Filariasis, supposed to be supreme in the list of insect-borne disease only next to malaria, is dealt with along with tropical eosinophilia, a disease of disease of doubtful etiology confined to the tropical and subtropical regions such as India. Fairly good details of the intestinal parasitic infestations with special reference to their pharmacotherapy are available. The common problem of resistant/ recurrent giardiasis is pointed taken up. The probability of hypogammaglobulinemia must be considered in children who fail to respond to repeated courses of antigiardial therapy. While dealing with neurocysticercosis, there is a due mention of the short course of 5 days of albendazole being as effective as 28-day course. Finally, the chapter carries a brief description of hydatid disease. The drug of choice in echinococcosis is albendazole, 15 mg/kg/day in 3 divided doses for 28 days. Four or five such courses at 15 days drug-free interval may be needed. Further, medical therapy may need supplementation with surgery.