The research aims to study the productive and economic efficiency of the dairy production sector within the farms of North Sinai Governorate Egypt, The results showed that the average number of heads of mixed cows and dairy-producing buffaloes within North Sinai Governorate has reached about 1464.5 and 114.3 thousand heads, respectively, during the period (2000-2020), and it has reached the general average of the milking head of dairy during the milking season is about 2785.1 kilograms, during the 2021 production season. The net head yield of mixed cows and buffaloes, respectively, amounted to about L.E 7449.2, 8718 at the actual size, compared to about L.E 8869.9, 10065.6 at the optimal size, and about L.E 10713.9, 15882.2 at the maximum volume of profits, which indicates the presence of lost income for the head of mixed cows and buffaloes, respectively, amounting to about L.E 1420.7, 1347.6 at the optimal size, and about L.E 3264.7, 7164.1 at the maximum volume of profits, at the level of the total sample farms, during the production season 2021. The research recommends increasing the used quantities of production elements combined and re-mixing them with each other in order to achieve the optimal use of them.