Non-Hodgkin’s lymphoma consists of a number of malignancies of the lymphatic system with differing patterns of incidence by age and sex, differing clinical courses and probably differing aetiologies. Both men and women in NI had a higher risk, but this was statistically significant only for women. There was little variation in risk by any of the socio-demographic variables studied. Geographical variation in risk was modest. The overall geographical pattern was the same for men and women, although more obvious for women, with an area of highest risk in eastern NI, extending through Louth and Meath to north Co. Dublin.