Skin cancers are one of the most common cancers in the Caucasian population. A constantly increasing number of nonmelanoma skin cancers and malignant melanomas is observed. The incidence of skin cancers is associated mainly with exposure to sunlight. Therefore, agricultural workers who work in open spaces are a particularly vulnerable group. Currently, studies on the pathogenesis of skin cancer focus on the molecular basis associated with ultraviolet radiation. This study is an attempt to summarize the current state of knowledge on this issue. There have been demonstrated mutations in different classes of genes associated with carcinogenesis, including protooncogenes, tumour suppressor genes, genes that control apoptosis, genes encoding transcription factors and DNA repair genes in patients with skin cancers. Mutations in the latter result in reducing the effectiveness of DNA repair and fixation of mutations. All changes at the gene level lead to structural changes, quantitative and dysfunction of proteins encoded by these genes. All these factors contribute to the process of carcinogenesis. Due to increasing number of skin cancers, it seems important to increase knowledge of the molecular basis of skin cancers. This knowledge could be crucial for predicting the course of the disease, and for the development of new therapeutic strategies.