Filariasis mediated immunomodulation against metabolic diseases is a recently identified novel phenomenon. There seems to be an inverse relationship between filarial infections and type-2 diabetes. Rapid elimination of filarial diseases, due to mass drug administration has somehow fueled the sudden and rampant increase in type-2 diabetes, at least in certain tropical countries, like India and Indonesia. Filarial infections are in a way unique, since they bring about immunomodulation, in contrast to inflammation which is triggered by viral and bacterial infections. This dampens immunity and confers better survival for the pathogen. However, this also attenuates chronic inflammation and insulin resistance and thereby confers protection against type-2 diabetes. This chapter elucidates the various immune mechanisms involved in immunomodulation against insulin resistance and type-2 diabetes induced by helminth infection.