In this research, the SNaPshot sequencing method was used for the first time in Venezuela for the diagnosis of mutations in exon 2 of the KRAS and NRAS genes, from DNA extracted from tumor tissue samples fixed with formalin and included in paraffin (FFPE) and was compared with Sanger’s method to determine the specificity and sensitivity, in the detection of mutations in the KRAS and NRAS genes. The gene discussed is NRAS; the disease is neoplasm.