The experiment entitled “Physiochemical analysis of oyster mushroom” was conducted at the Nuclear Institute for Food and agriculture (NIFA), Peshawar during the month of March, 2014. The objective was to compare the composition of fresh and dried oyster mushroom. The maximum (19.33mg/100g) vitamin c, (0.75%) crude fat and (2.83%) fibre content was noted in oven dried mushroom, while maximum (77.66%) moister content and (7.06%) protein content was observed in fresh mushroom. Ash was high in room dried mushroom. Hence oven dried mushroom is recommended for high production of vitamin C, Fats and Fiber content while for high production of moister content and protein content fresh mushroom is recommended.