Ultrafiltration (UF) is widely used in the dairy industry for concentration and fractionation of milk proteins. However, the economy of operation depends on the flux during operation. Flux can be optimised by controlling operational parameters. UF of buffalo skim milk was carried out using laboratory module hollow fibre membrane. Skim milk was adjusted to different temperatures and p^H before subjecting to UF. Results indicated that UF operation could be carried out at 50°C with p^H 7.0 or 8.0 to have maximum flux and minimum fouling of membrane during UF of buffalo skim milk.