This study was conducted to determine the physical characteristics of the hazelnut in two forms and to evaluate the impact of cooking on the physicochemical properties. The results showed that the weight of the African hazelnuts ranged from 5.03±0.81 to 22.15±3.93 g, lengths ranging from 2.0±0.07 to 3.56±0.15 cm, widths from 3.29±0.31 to 3.29±0.31 cm. Lengths and widths of whole fruits and seeds showed no significant differences (p <0.05). The most dominant parameters are carbohydrates, fats and proteins. Fat (33.92±6.02-31.73±3.08), protein (11.29±2.15-10.20±2.28), fiber (2.37±0.67-1.45±0.05) and dry matter (94.92±0.47-93.63±1.91) contents (%) decreased significantly (p <0.05) after cooking, while carbohydrates (52.15±4.37-55.75± 5.62) reducing sugars (1.25±0.11-2.08±0.35) and total sugars (5.58 ± 0.87 -6.15±1.3) contents increased. Mineral composition of African hazelnut flours is dominated by potassium, magnesium, phosphorus and calcium. The potassium (5582.15±58-5314.65±204 mg/Kg), magnesium (5243.8±226 -4003.8±177 mg/Kg), manganese (31.53±0.8 -30.93±0.7 mg/Kg), iron (30.33±0.45-26.25±0.32 mg/Kg), calcium (1925±63-1167.7 ±18 mg/Kg) and sodium (255±3.54-241.7±1.92 mg/Kg) contents decreased after cooking while zinc content (21.47±1.27-241.7 ± 1.92 mg/Kg) increased.