Intact monomeric type I collagen was purified from fetal bovine skin by a simple and time saving procedure. Saline precipitates of mixed skin collagens, in 4 M NaCl, were extracted with a limited volume of dilute acetic acid, taken in the proportion of 1 ml per g of original wet skin; NaCl in the precipitate was not removed by dialysis. The salt concentration in the extraction medium in the above conditions, selectively solubilized type I collagen.