A nuclear magnetic resonance (NMR) imaging method in radiology is used to obtain images of watercore and its distribution in ‘Red Delicious’ apples ( Malus domestica Borkh.). The uneven distribution of mobile water and its NMR relaxation times, spin-lattice ( T 1 and spin-spin ( T 2, produce signals that are used to reconstruct cross-sectional images. From the variation of signal intensity in the images, detailed internal structures of apple fruit, including petal bundle, endocarp, outer limit of carpel, dorsel bundle of carpel, cortex of receptacle, pith of receptacle and seeds, can be discerned. Both the normal and watercored tissues can also be clearly differentiated on the images. Based on NMR images, watercore occurred primarily in the area ±20 mm from the center of the fruit of an affected apple, and the area most affected was between 5 and 10 mm from the center, toward the stem end.