The aims of this study were to measure the thickness of the palatal masticatory mucosa and determine its histologic characteristics with reference to autogenous grafting. Thirty-two fully dentate, cadaver hemimaxillae were examined (from 13 men and 3 women; mean age, 57.1 years). The thickness of the palatal masticatory mucosa was assessed at 24 standard measurement points on the sectioned specimens after decalcification, and then the specimens were processed for embedding in paraffin, sectioned, and stained with hematoxylin and eosin. The thickness of the palatal masticatory mucosa varied by tooth site as follows: 3.55 ± 1.09 mm (mean ± SD; distal canine), 3.51 ± 0.99 mm (distal first premolar), 3.28 ± 1.07 mm (distal second premolar), 2.83 ± 1.00 mm (midline first molar), 2.92 ± 1.03 mm (distal first molar), and 3.15 ± 1.66 mm (distal second molar). The thickness also varied according to distance from the cementoenamel junction (CEJ): 2.35 ± 0.79 mm at 3 mm below the CEJ, 2.65 ± 0.77 mm at 6 mm, 3.52 ± 0.94 mm at 9 mm, and 4.29 ± 1.14 mm at 12 mm. Histologic analysis showed that the thickness of the lamina propria decreased toward the posterior palatal area and midpalatal suture, while that of the submucosa increased. These results suggest that the most appropriate donor site for gingival autogenous grafting is the region 3 to 9 mm below the CEJ between the distal surface of the canine and the midline surface of the first molar. (Int J Periodontics Restorative Dent 2014;34:115-121. doi: 10.11607/prd.1530)