Milk fever, a metabolic disease, affects dairy animals usually within one or two days after calving, resulting in a huge reduction in milk production and thus becomes economically most important. This study, conducted in five milkshed districts of Tamil Nadu, has estimated the economic losses arising from milk fever, based on the data collected from a random sample of 557 milk fever affected bovines (516 cows and 41 she buffaloes) during 2005-08. For assessing economic losses caused by milk fever, cost of medicines, veterinarian’s fee, cost of additional labour utilized, loss due to reduction in milk output, cost of animals dead and culled have been considered. The prevalence of milk fever has been found 13.67 per cent in cows and 11.99 per cent in buffaloes across the study districts. The total loss has been found as Rs 1,068 per affected cow and Rs 665 per buffalo. Taking into account the observed prevalence of milk fever, the population of milch cows and buffaloes and the per animal loss due to milk fever has been estimated to be of Rs 40.62 crore in the state, which is a substantial damage to the dairy farming community. Some suggestions for prevention and management of milk fever have been given in the study.