To satisfy consumer desires for more health advantages, food products must be fortified. The sensory, proximate, and microbiological characteristics of biscuits enriched with Pleutotus ostreatus at different inclusion levels were assessed. The manufacturing of wheat flour, baking of mushroom powder biscuits (MPB), microbiological examination of MPB, proximate analysis, and sensory evaluation of MPB were all done using standard procedures. The fortified mushroom biscuit had varying mushroom compositions, ranging from 50-100% (sample A-F). The results showed that the composition with 90% mushrooms had the highest bacteria count (62 CFU/ml) while 50% had 1 CFU/ml. Various microorganisms were tentatively identified from MPB, including Staphylococcus warnei, Bacillus niacin, Kluyuera georgiana, B. circulans, B. licheniforms, B. megaterium, B. barbaricue, B. cereus, B. simplex, Aspergillus flavus, A. niger, and P. ostreatus. According to the study, the nutritious value of wheat cookies supplemented with mushrooms rose as mushroom powder concentration rose. The value of the carbohydrates was the highest at 73%, while the value of the ash content was the lowest at 2%. Sample D, which contained 50% each of flour and mushrooms, had the highest crude fibre level. Higher mushroom powder concentrations reduced the fortified biscuit's overall acceptability (OA). Sample E (10% mushroom) had the highest OA, scoring 9.30 0.21 for both texture and flavour. Based on the findings, it is recommended that the commercial production of biscuits be carried out at a 50% level of mushroom inclusion for the best nutritional, essential mineral and sensory efficacy. Keywords:- Mushroom, Biscuit, Proximate, Sensory, Nutritional, Mineral.