Based on population statistics and institutional reviews, the median age of patients developing non-Hodgkin's lymphomas (NHL's) is around 65 years. A review of retrospective studies suggesting that increasing age imparts an adverse prognosis in patients with NHL's is presented. Interpretation of this data is often confounded by referral bias of patients to specialized centres, multiple other NHL-related risk factors and inadequate chemotherapy administration due to age and toxicity related dose reductions. These factors, as well as alterations in tumour-host biology and comorbid diseases which result in changes in pharmacokinetics and pharmacodynamics, are discussed as possible reasons for poorer outcome in the elderly. In an effort to develop better tolerated and thus more effective combination chemotherapy for older patients, a number of prospective single arm and randomized clinical trials of novel regimens have been undertaken. Improved rates of disease remission and overall survival appear often to have been achieved at the expense of greater morbidity and mortality. Ongoing attempts to improve the therapeutic index include the application of chronic oral chemotherapy, brief duration intensive therapy and fractionation of standard drug doses as well as incorporation of myelo-preserving haematopoietic growth factors. The possibility of developing flexible, "customized" therapy for elderly patients is discussed.