Colorectal cancer (CRC) is one of the most common cancer worldwide with approximately 2 to 5% of all colon cancers are associated with well-defined hereditary factors. Hereditary nonpolyposis colorectal cancer (Hereditary Nonpolyposis Colorectal Cancer), also known as Lynch syndrome (LS), is the most common form of hereditary CRC characterized by an early age of onset and follows the autosomal dominant inheritance pattern. HNPCC is caused by the alteration in four mismatch repair (MMR) genes. Immunohistochemistry (IHC) and microsatellite instability (MSI) testing, followed by conventional Sanger sequencing reliably identify the majority of mutations. However, methods to identify other underlying variants or genomic rearrangements of HNPCC have emerged. In addition to the clinical characterization and evaluation of HNPCC patients, the implementation of screening strategies for both affected and unaffected CRC patients together with the accelerated advancement in molecular testing methods will shed light on a more comprehensive detection of HNPCC. In this review, the approaches for the selection of high-risk HNPCC and molecular testing performed over the past few years are discussed.