Secretion of venom in the venom glands of Vipera palaestinae was studied by measuring the protein content and enzymatic activities of L-amino acid oxidase (LAO), phosphodiesterase (PDE), and benzoylarginine ethyl esterase (BAEE). These were tested in the accumulating venom and gland homogenates at 0, 2, 3, 4,6, and 15 days after an intitial emptying of the venom glands by milking. Changes in the total activities of the enzymes and in the protein concentration were found in the venom samples, but not in the homogenates, at the different intervals after milking. In the venom the total activities of LAO, PDE, and BAEE were higher the longer the time intervals from the initial milking. When the data were fit by a straight line, the fluctuations from the line were of opposite signs for LAO and PDE at the 3- and the 4-day intervals. There were no significant correlations between the specific activities or between the changes in the specific activities of any two of the enzymes at any time interval. It is concluded that each of the enzymes is secreted at a rate independent of the other two; this pattern of secretion can best be described as nonparallel.