Porodaedalea pini is a medicinally important mushroom with antioxidant, cytotoxic, immunostimulating, antitumor, antiviral and immunomodulating activities. Therefore, in this study, P. pini methanol extract and isolated compounds from the methanol extract were tested for cytotoxic activities against DLD-1 (colorectal cancer) and CCD-18Co (human colon fibroblast cell line) by using Alamar Blue assay. Cytotoxic activity on DLD-1 was decreased in the order of P. pini methanol extract> 4-(3,4-dihydroxyphenyl)but-3-en-2-one (3)> pinoresinol (2)> ergosta-7,24(28)-dien-3β-ol (1). P. pini methanol extract was determined to have the best cytotoxic activity with the lowest IC<inf>50</inf> value on DLD-1 (IC<inf>50</inf>: 25.33±0.29 µg/mL) and the highest IC<inf>50</inf> value on CCD-18Co (434.30±1.45 µg/mL). Within the scope of the findings, it is thought that P. pini mushroom can be used as a new and natural agent in the treatment of colorectal cancer.