The antioxidant and cholinesterase inhibitory activities of the acetone and dichloromethane (CH 2 Cl 2 ) extracts of the by-products (heads, shells, and tails) of Pandalus borealis, Pandalus hypsinotus, and Pandalopsis japonica belonging to the family Pandalidae were investigated and their bioactivities were compared. The antioxidant and cholinesterase inhibitory activities of the organic solvent extracts of three shrimp by-products were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2´-Azino-bis[3ethylbenzothiazoline-6-sulfonic acid] (ABTS + ) radical scavenging activities, reducing power and xanthine oxidase (XO) inhibitory activity assays and Ellman's colorimetric method. The extracts of P. hypsinotus exhibited the highest antioxidant and cholinesterase inhibitory activities. The acetone extracts showed more potent activities toward antioxidant and cholinesterase inhibition compared with the CH 2 Cl 2 extracts. Furthermore, the total carotenoid contents of the acetone extracts were higher than those of the CH 2 Cl 2 extracts. Thus, the carotenoid contents may affect antioxidant and cholinesterase inhibition. Our results suggest that the shrimp by-products could act as a nutraceutical agent to prevent oxidative stress and Alzheimer's disease.