This study aimed to evaluate the nutritional composition of various edible and medicinal mushrooms and assess their potential as alternative food sources in response to increased meat consumption, which poses environmental and health risks. The crude protein, crude fat, carbohydrate, dietary fiber, and vitamin C contents of 17 edible and medicinal mushroom species, including Flammulina velutipes, Pleurotus ostreatus, Pleurotus eryngii, Agaricus bisporus, Lentinula edodes, and Wolfiporia extensa, were systematically analyzed. Pleurotus ostreatus‘Suhan 2’ and P. eryngii‘No. 2’ showed high crude protein and carbohydrate contents, suggesting excellent potential as alternative protein and energy sources. Flammulina velutipesvarieties ‘TO22’ and ‘Aram’ exhibited relatively high crude fat contents, whereas P. eryngii‘No. 2’ and P. ostreatus‘Suhan 2’ had high vitamin C levels, suggesting a beneficial role in immune enhancement. In contrast, the medicinal mushroom W. extensa had relatively low protein and dietary fiber contents, limiting its potential as an alternative protein source compared to the other edible mushrooms. Nonetheless, it may provide other health benefits. The present study provides foundational data for the utilization of mushrooms as sustainable alternative food resources, supporting efforts to mitigate environmental impacts of meat production and improve dietary health.