Small ruminant lentiviruses (SRLVs), it is a group, which include, maedi-visna virus (MVV), and caprine arthritis encephalitis virus (CAEV). They cause multisystemic, chronic infections and inflammatory lesions in the affected goats and sheep. SRLVs have a worldwide distribution. Since there are no vaccines or effective drugs available against SRLVs infection, and control of the disease relies mainly on the identification and elimination of infected animals. Therefore, the broad use of sensitive and specific diagnostic tests is immensely important. The diagnosis is based either on the detection of SRLV-specific antibodies using serological tests, or on detection of the viral genome by molecular assays. However, early and definitive diagnosis is complicated and a “gold standard” test with broad applicability have not been developed yet. Major obstacles in the development of effective diagnostic tests are high genetic variability of SRLVs associated with frequent mutations, recombination, and interspecies transmission. Then, the measurement of humoral immune responses of small ruminants in terms of late seroconversion and intermittent and epitope-specific antibody production. The purpose of this article is to provide an overview of the methods routinely used to diagnose infected animals and to discuss current and future prospects, challenges and limitations in SRLV diagnosis.