Mushrooms have been used as medicines in eastern countries for centuries. Numerous scientific researches have been conducted and as a result of these studies, fungi have been shown to strengthen the immune system and significantly protect health. Mushrooms are widely used by humans because of their nutritional value and medicinal properties. It is used in the treatment or prevention of many diseases by extracting the active substances present in their compositions. Today, chemotherapy and surgical applications are frequently used for cancer patients. However, these methods have not been fully effective in many cancers. In recent years, the trend towards various natural resources as well as medical treatment to prevent cancer has been increasing. Mushrooms are one of these natural resources. Mushrooms; due to its anti-cancer, antioxidant, antimicrobial and liver protective properties, it is used by many pharmaceutical companies in R & D studies. The search for new drugs to eliminate cancer is one of the most important needs of today. Therefore, the aim of this study was to evaluate the effect of Hericium coralloides, Lactarius deliciosus, Lepista nuda, Pleurotus ostreatus, Suillus collitinus fungi on human colorectal cancer cells (HCT116). Fungal extracts were prepared using Soxhlet extraction method. 50% of the maximum inhibitory concentration (IC50) values were determined by 3- (4,5-Dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT method) by applying to the cells for 24, 72 hours and 7 days. Cell morphology was evaluated with inverted microscope. As a result, Hericium coralloides, Lactarius deliciosus, Lepista nuda, Pleurotus ostreatus, Suillus collitinus fungal species reduced HCT116 colorectal cancer cell proliferation in low doses. However, more detailed analysis is needed to understand the mechanism of death.