Abstract: Long non-coding RNA (LncRNA) are a diverse class of RNA with transcripts longer than 200 nucleotides and limited protein coding potential. Emerging evidences show that dysregulated expression of LncRNA plays an important role in many complex human diseases, including cancer. In this review, we summarize the diagnostic sensitivity, specificity and validity of LncRNA as diagnostic or prognostic marker in various biological samples including tumor tissue, whole body fluids and exosomes to evaluate its clinical value.