McIntosh apple (Malus sylvestris Mill.) fruit shape was influenced by position in the blossom cluster, rootstock and strain and was correlated with Mg content of leaf tissue. High Mg content of leaves was associated with large length to diameter (L/D) ratios of fruit. The effects of rootstock and strain were conditional; in years of short apples, the L/D ratio of fruit approached a common small value regardless of rootstock or strain; in years of more elongate apples, the L/D ratio of fruit was more influenced by rootstock or strain. In general, large L/D ratios were associated with shallow stem-cavities.