Three lamb pregastric enzymes, isolated from the commercial extract from the tongue and epiglottal region of lamb, have been used to catalyze the hydrolysis of a series of 4-nitrophenylalkanoate esters (C2–C12) at 37°C, pH 7.2 and maximum activity was obtained against the decanoate ester in all cases. Burst kinetics were observed for activity of the principal lipase component against the decanoate ester. This enzyme was also used as a catalyst for the hydrolysis of monoacid triglycerides (C4:0 to C10:0) at 35°C, pH 6.5 and maximum activity was obtained against tributyrin (C4:0). A suggestion is made for orientation of ester substrates within the active site of the enzymes.