Today, colorectal cancer is regarded as a heterogeneous disease. Its heterogeneity is caused by genetic alterations, molecular aberrations, different developing pathways as well as by micro- and macroenviromental agents. In the last decade, beside the classic genetic model for colorectal tumuorgenesis that follows the adenoma-carcinoma sequence, an alternative pathway has been identified. This pathway is called the serrated pathway and it is responsible for approximately one third of all colorectal lesions. Beyond their dissimilar molecular characteristics, these tumours also show different macroscopic and histologic appearance. Moreover, their malignant potency and progressive ability distinguish them from tumours of the classic genetic model. The aim of this review is to summarize the molecular and pathologic features of serrated lesions and the serrated pathway to colorectal cancer and to highlight their clinical impact. Orv Hetil. 2018; 159(6): 206-2014.