The study has analysed the value chains of milk and milk products in the co-operative and private dairy plants in the Salem district of Tamil Nadu based on the data collected from one co-operative plant, one private plant, five milk transportation routes, ten co-operative societies, ten private milk collection centres and six chilling centres for the year 2007-08. The overall average procurement cost per litre of milk has been found higher for the co-operative dairy plant than the private plant due to increased cost on milk transportation, chilling and reception. The co-operative plant has been revealed more efficient in the manufacture of toned milk, standardized milk, full cream milk and ghee whereas the private plant has an edge over co-operative dairy plant in the manufacture of butter and SMP (skimmed milk powder). The marketing cost of toned milk, standardized milk, full cream milk and SMP has been found lower for private dairy plant and of butter and ghee for the co-operative dairy plant. The products which could earn a higher value after passing through the value chain are milk peda, khoa and SMP in the co-operative plant; and ice cream, Mysorepa and ghee in the private plant. The marketing margins and marketing efficiency have been found higher in toned milk, standardized milk and butter for the private plant and in full cream milk, ghee and SMP for the co-operative plant.