The effect of fermentation on the proximate and anti-nutritional properties of rice flour enriched with mucuna beans was investigated in this study. The rice-mucuna beans flour blends were formulated in various ratios and fermented for 72 h. The predominant moulds isolated during the fermentation were Aspergillus flavus, Aspergillus fumigatus, Geotrichum candidum and Rhizopus stolonifera. After fermentation, the protein and ash contents of the flour blends increased while carbohydrate, lipid and fibre contents reduced. However, there was no notable difference in the moisture content of the fermented flour blends. Fermentation also caused a significant reduction in the tannin, phytate and oxalate contents of the rice-mucuna beans flour blends. Nutritional benefits of rice flour can be enhanced through enrichment with mucuna beans and fermentation process. Therefore, fermented rice-mucuna beans flour blends have potential application in managing protein-energy malnutrition (PEM) in developing countries. Key words: Fermentation, improvement, anti-nutrient, rice flour, mucuna beans.