Molecular diagnostic techniques are used for the diagnosis and monitoring of viral infections. The performance of the in vitro diagnostic assays is important for an accurate and prompt diagnosis. Positive clinical samples or reference materials (RMs) are essential for the development, validation, and verification of the assays for molecular diagnostics-based virus detection. Since it is difficult to obtain positive clinical samples, the need for RMs with the required properties is increasing. In this review, the types, manufacturing methods, and verification of RMs for genetic testing of viruses are discussed along with the producers involved in their production, sale, and distribution.