In this research, an equation for estimating the leaf area was derived for the chestnut tree by using 18 chestnut genotypes and by measuring the lamina width, length and leaf area without damage being caused in 2004-2005. Multiple regression analysis for the genotypes was separately performed. The proposed leaf area (LA) estimation model is: LA = 3.36 + 0.11 L-2 - 0.26 L-2/W-2 + 1.1 W-2, R-2 = 0.988, where LA is the leaf area, W is the leaf width and L is the leaf length. The model was validated by measuring leaf samples of the SE-21-2 genotype in different climate conditions in 2004-2005. (c) 2006 Elsevier B.V. All rights reserved.