A new classification of lymphoid neoplasms, mostly based on existing terminology, is proposed by the International Lymphoma Study Group. The proposed classification was reached through a consensus of the members, despite their diverse backgrounds, and consists of a listing of currently recognized clinicopathological entities. These tumours are divided into three major categories: B-cell neoplasms, T-cell and postulated natural killer cell neoplasms, and Hodgkin's disease. The characterization of each entity is based on a synthesis of all available information. This concept departs from a purely morphological approach to lymphoma classification, which is considered to be inadequate, because many biologically distinctive lymphoma types can exhibit a broad and overlapping morphological spectrum. Some entities are provisional, pending further data to confirm that their recognition is reproducible. The salient clinicopathological features of each entity are summarized in this review.