In order to investigate the effects of Yoyo and Swedish bitters on arylesterase activity in very low density lipoprotein (VLDL), 40 male albino rats were divided into 6 groups; i, 3-week Yoyo bitters. ii, 3-week Swedish bitters. iii, 3-week control. iv, 6-week Yoyo bitters. v, 6-week Swedish bitters, vi, 6-week control. Daily weight of animals were determined and dosage of bitters corresponding to weight of each animal was administered. VLDL was isolated by a simple precipitation procedure and Arylesterase activity was determined. There was no significant difference in the effect of both Yoyo and Swedish bitters on arylesterase activity (P>0.05) as compared with the control suggesting that neither bitters affect the VLDL arylesterase activity,. However, there was an increase in the activity of arylesterase (P