Objective: The present study is aimed at optimization of concentration of substrate (pomegranate peel extract) for the production of Ellagic acid using Aspergillus niger and Rhizopus oryzae. Methods: Test organisms were isolated and identified using standard microbiological techniques. Collected pomegranate peels were dried, grained and used as the substrate for solid-state fermentation. Prepared spore suspension of the test organisms was inoculated and incubated at room temperature. At regular intervals of 24 h, samples were drawn and subjected to analysis of reducing sugar, soluble proteins, hydrolysable tannins and production of extracellular tannase using standard methods. Results: The results of the present investigation demonstrated the optimum substrate concentration for the active conversion of ellagitannins to ellagic was 15g of A. niger, 20g for R. oryzae and 15g for mixed culture. Conclusion: From the current work, it was concluded that solid-state bioprocessing of fruit substrates and fruit wastes using fungi has shown to enrich phenolic antioxidants and improve phytochemical consistency.