A quantitative determination of alpha -tocopherol in Arbutus unedo leaves was established by TLC-densitometry and colorimetry. Data obtained by TLC-densitometry were compared with those obtained by colorimetry. Also, the alpha -tocopherol content in leaves collected at different times of the year was studied comparatively. The highest amount of alpha -tocopherol was found in the March collection. (C) 2001 Elsevier Science B.V. All rights reserved.