Ten trees of Eucalyptus globulus Labill. from three different sites within Portugal were felled at 12–15 years, to study fibre length variation in bark and wood. The fibres of E. globulus were morphologically similar in bark and wood, but generally longer in the bark (on average, 0.97 mm in wood and 1.11 mm in bark). The axial variation was small and opposite in wood and bark; fibre lengths decreased in the wood and increased in the bark from the base to the top. Fibre length in wood increased significantly from pith to bark at all height levels. The measurement of fibre length at 1.3 m height level was representative for the tree average for both wood and bark.