Objective: To investigate PON 1/Aryl activities in basketball players with or without α-T supplementation pre- and post-training. Vitamin E (α-tocopherol, α-T) reduces lipid peroxidation. Paraoxonase 1/arylesterase (PON 1/Aryl) activities are closely related to oxidation and atherogenesis. Subject/Methods: Blood was obtained from 10 players pre- (group A), post-exercise (group B) and after 1 month on α-T (200 mg per 24 h orally) supplementation pre- (group C) and post-exercise (group D). Lactate, pyruvate, muscle enzyme activities, creatine kinase, lactate dehydrogenase and total antioxidant status (TAS) were measured with commercial kits. Catecholamines and α-T were determined with high-performance liquid chromatography methods and PON 1/Aryl activities spectrophotometrically. Results: Lactate, pyruvate, muscle enzyme activities and catecholamines were increased (P<0.001) in all groups post-training. Alpha-T levels remained unaltered pre- vs post-exercise. TAS was decreased in all the groups post training. PON 1/Aryl activities were significantly decreased post-exercise (group B) (PON1: 65±12 U min−1 ml−1, Aryl: 58±14 KU min−1 ml−1) as compared to those pre-exercise (group A) (PON1: 142±16 U min−1 ml−1, Aryl: 114±12 KU min−1 ml−1, P<0.001). In contrast, the studied enzyme activities remained practically unaltered after α-T supplementation pre- vs post-training. Both enzyme activities positively correlated to TAS (r=0.60, P<0.001). Conclusions: Alpha-T supplementation may result in protection of the enzyme PON 1/Aryl activities from free radical production.