Comparing the conventional treatment after the interferon alpha treatment the number of hematologic as well as cytogenetic responses increases. With the cytogenetic response is associated a longer survival. Today is interferon alpha considered to be the first line treatment in those patients with chronic myeloic leukaemia, who are not candidates for alogenic bone marrow transplantation. The combination with cytosinarabinoside can reduce the number of Ph positive metaphases.Forty-three previously untreated patients with CML in chronic phase were randomly assigned to receive either IFN alpha 2 b (5MU sqm/daily) or IFN alpha 2 b in the same dosage plus monthly courses of low-dose AraC. The aim were complete hematologic remission at 6 months and cytogenetic response at 12 months.A complete hematologic remission occured in 61.9% patients with single IFN alpha 2 b and in 78.9% patients with combination therapy. A cytogenetic response was present in 28.5% and in 42.2% patients with combination therapy. One of 21 patients treated with IFNalpha/AraC therapy achieved complete (5.2%), 4 partial (21%) and 3 minor (16%) cytogenetic response. The side effects were more significant in the group receiving combination therapy.Based on published data that shows a survival advantage for patients who achieved any cytogenetic response and high rate of cytogenetic response which we observed in our population we believe that IFN plus AraC regimen could be a front-line therapy for CML.