The study aimed to find out the economics of major breeds of cow in selected areas of Sindh and Azad Jammu and Kashmir. It is based on primary data of 130 livestock farmers, selected through simple random sampling technique. Shares of different feed resources in total feeding cost have been determined and cost-benefit analysis of milk production by ecological zones was also conducted. Wide variations in share of feed sources in total feeding cost per annum, milk productivity and profitability of main cow breeds across selected areas have been observed. Concentrate feeding is the main cost item for cow milk production in irrigated areas of Sindh and constitutes more than half (54 %) of the total feeding cost per annum. While, in coastal and desert areas of Sindh, and mountainous - AJK wheat straw is the major cost item and shares more than half of the total feeding costs per annum (51 - 58 %). Mean milk productions per lactation of Red-Sindhi breed were 1845 lit and 1590 lit in the irrigated and coastal areas of Sindh, respectively. Productivity of Thari breed in desert areas of Sindh and that of non-descript cow breed in AJK was 1411 lit and 2008 lit per lactation, respectively. Cow milk production is profitable farming activity in irrigated areas of Sindh and mountainous-AJK with benefit-cost ratios of 1.5 and 1.4, respectively. While, benefit-cost ratios of cow milk production were 1.0 and 0.7 in desert and coastal areas of Sindh, respectively, indicating subsistence nature of cow farming in these ecologies.