The present retrospective analysis is based on data of 213 patients with chronic myeloid leukaemia (CML). They were treated with interferon (IFN)alpha-2C (Berofor) at daily doses of 3.5 MU subcutaneously (s.c.), alone or in combination with low-dose ara-C or hydroxyurea, according to four consecutive studies of the Austrian CML Study Group. Comparisons were made between 41 patients aged > or = 60 years and 172 younger patients. The elderly patients (median: 64 years; range: 60-73) showed similar pretreatment characteristics compared with the younger group, but included a higher percentage of Sokal Stage three (51 vs 20%). Median observation periods were similar (38 vs 39 months), whereas the duration of IFNalpha treatment was shorter in the elderly group (median 57 vs 42 weeks). The rate of overall haematological responses (73 vs 78%) and complete haematological response (44 vs 54%), was similar in both cohorts. Differences seen in partial (5 vs 12%) and complete cytogenetic response (10 vs 13%), were not statistically significant, but a tendency in favour of the younger cohort had to be noted. Summing up, in elderly patients acceptable rates of haematological and cytogentic response can be expected after treatment with IFNalpha alone or in combination with LD ara-C or HU.