Pigeon pea (Cajanus cajan) is a leguminous crop rich in protein and widely cultivated in Nigeria but underutilized due to high anti-nutritional properties. Several processing methods such as fermentation using non-pathogenic micro fungi have been used to address these problems. This study evaluated the effect of fermentation on the functional and proximate properties of pigeon pea using Rhizopus species. The following ranges of values were obtained for bulk density, water absorption, oil absorption and swelling capacities (0.74-0.98g/ml; 71.67-189.00%; 120.00-205.00%; 6.81-10.93g/ml), respectively. Values of proximate composition were in ranges of 6.67-7.87, 16.09-22.09, 2.83-4.00, 0.84-1.23,1.33- 2.00 and 65.47- 71.35% for moisture, protein, ash, fat, fibre and carbohydrate contents, respectively. Improvement in functional and proximate properties of fermented pigeon pea flour were observed. Hence, it can also serve as functional and supplement ingredients in different food formulations.