Heat stress and helminth infestation are major constraints to profitable sheep farming in the tropics. H. contortus is a major deadly helminthes which causes great havoc to small ruminant animals in the tropical regions. This work determines the effect of coat colour on Heat stress physiological and haematological parameters among West African Dwarf Sheep. It also determines the response of the different coat colour type of WAD sheep to H. contortus challenge. The study was carried out at in a tropical region . West African Dwarf sheep with different coat colour types (black , brown with extensive white markings, brown mouflon, badger face and black with extensive white markings) were used for the experiment. Badgerface sheep can withstand heat stress while brown sheep can tolerate H. contortus more than other coat colour types.Breeding of black sheep and others with dark pigmentation should be done under intensive care against heat stress. Male sheep can withstand harsh/hot climatic condition better than females. The genetic superiority of brown coat colour should be taken into consideration when designing breeding programmes for genetic resistance against helminthes.