BACKGROUND: Attenuation of the epidemic increase in non-Hodgkin's lymphoma (NHL) incidence has recently been reported in the USA and Nordic European countries. After two decades of steadily increasing NHL, this study sought to ascertain whether a similar stabilisation might have taken place in Spain in recent years. PATIENTS AND METHODS: NHL cases were drawn from 13 population-based Spanish cancer registries with a record of at least 10 years of uninterrupted registration during the period 1975-2004. Overall and age-specific changes in incidence rates were evaluated using change-point Poisson models, which allow for accurate detection and estimation of trend changes. RESULTS: A total of 21 335 NHL cases (11 531 male and 9804 female) were identified. Although overall age- and registry-adjusted incidence rates rose by 5.74% annually among men and 6.58% among women across the period 1975-95, a statistically significant change-point was nevertheless detected in both sexes in 1996, followed by stabilisation. CONCLUSIONS: In Spain, NHL incidence levelled off in 1996 after a sharp increase during the 1970s and 1980s. This stabilisation is, partially at least, linked to the decrease in incidence of AIDS-related lymphomas among young adults.