Abstract: Fluorescence in situ hybridization (FISH) is a cytogenetic technique that detects changes in target genes and chromosomes using the hybridization of fluorescent-labeled probes to specific DNA fragments on chromosomes. Lymphomas are among the most common malignant tumors worldwide. These tumors have complex subtypes with various responses to therapy and different prognosis. The different lymphomas demonstrate abnormal gene and chromosome characteristics, which may be associated with patient prognosis, such as in diffuse large B cell lymphomas, mucosa-associated lymphoid tissue lymphomas, follicular lymphomas, and anaplastic large cell lymphomas. FISH has been widely used to study the molecular genetics of lymphomas and to provide scientific evidence and clues for clinical diagnosis and prognosis. This article gives a brief review of the applications of FISH in the study and diagnosis of different types of lymphomas.