AbstractA new procedure is described for isolating and measuring squalene in plasma and in several organs of the rat. The unsaponifiable material was fractionated by normal phase HPLC on a silica gel column using a mobile phase consisting of hexane/propanol‐2/water. The eluate was monitored at 215 nm. The squalene in the hydrocarbon fraction thus collected was than quantified on an analytical column eluted with hexane. Squalene concentrations ranging from 3 to 200 μg per ml of plasma or per g of fresh tissue were accurately measured. The results obtained agree with those of the squalene assays carried out by gas chromatography on a packed or capillary column.