The purpose of the study was to enhance the lactic acid production using fruit peels by conventionalrnmethod and to optimise by Response Surface Methodology. The total sugars, cellulose, phenolics andrnreducing sugars were lower in citrus peel than the mango peel; and total flavonoids were higher inrncitrus peel than the mango peel. Lactic acid production of 0.51 and 0.9 g/L was obtained from citrusrnand mango peels, respectively at 3% substrate concentration. Conventional mango peel (30%) batchrnsubmerged fermentation at optimum pH 6.0 and temperature 35 ºC produced 7.0 g/L of lactic acid byrnRhizopus oryzae NCIM 1009. The statistical analysis of factorial study showed 7.25 g/L of lactic acidrnwith yield 0.65 g/g in 60 h at 35 ºC were the best conditions. The optimised mango peel fermentationrnconditions produced by six times more lactic acid and yield (g/g) based on substrate consumed.