There are limited data characterizing the subtype-specific incidence of lymphoid neoplasms in the World Health Organization (WHO) Classification era. Data were obtained on all incident lymphoid neoplasms registered in Australia during . Subtypes were grouped using the InterLymph nested hierarchical classification, based on the 2008 WHO Classification. Temporal trends were examined using Joinpoint regression; average annual percentage change in incidence was computed. Multiple Poisson regression was used to compare incidence by sex and age. The incidence of all non-Hodgkin lymphoma (NHL) increased by 2.5%/year during 1982-1996 and was stable thereafter. During 1997During -2006, several mature B-and natural killer (NK)-/T-cell NHL subtypes increased in incidence, including diffuse large B-cell (1.3%/year), follicular (2.5%/year), Burkitt (6.8%/year), marginal zone (13.2%/year), mantle cell (4.2%/year), peripheral T-cell lymphoma (4.7%/year) and plasmacytoma (7.1%/year). While chronic lymphocytic leukemia incidence was stable, small lymphocytic lymphoma incidence declined (8.1%/year). Hodgkin lymphoma (HL) incidence increased during 1997-2006 (2.2%/year), both classical (4.3%/year) and nodular lymphocyte predominant (12.1%/year) HL. Diagnostic artifact, evidenced by a sustained decline in the incidence of NHL not otherwise specified (NOS; 5.8%/year) and lymphoid neoplasms NOS (5.6%/year), limits the interpretation of temporal trends for some subtypes. A marked male predominance was observed for almost all subtypes. Incidence of mature B-and NK-/T-cell NHL subtypes increased sharply with age, except for Burkitt lymphoma/leukemia. For HL subtypes, a bimodal age distribution was only evident for nodular sclerosis HL. Variation in incidence patterns over time and by sex and age supports etiological differences between lymphoid neoplasm subtypes.Lymphoid neoplasms, including non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL), plasma cell neoplasms and lymphoid leukemias, collectively represent the fifth most common malignancy in Australia. 1 Their etiology is largely unknown, with specific infections and immunodeficiency being the only established risk factors. Descriptive studies in the United States and Europe show differences in demographic 2-4 and temporal 3,5 incidence patterns between lymphoid neoplasm subtypes, which, together with observations from analytical studies, 6 suggest differences in etiology.There have been few comprehensive studies of subtypespecific incidence patterns. [2][3][4]7 The existence of multiple classification schemes 8 and variable exclusion criteria make comparisons challenging. These schemes include the Working Formulation (WF, 1982), the Revised European-American Lymphoma (REAL) Classification (1994) and the World Health Organization (WHO) Classification of Tumours of