Interferon-alpha (INF-alpha) is an effective anti-neoplastic and anti-viral drug. Treatment with INF-alpha is frequently complicated by adverse effects, which may rarely be immune mediated. We report 2 patients with Ph+ chronic myeloid leukemia (CML) who developed autoimmune thrombocytopenia while receiving months of treatment with INF-alpha. This complication responded well to discontinuation of interferon and administration of steroids treatment. Here, we also summarize the literature on INF-alpha induced autoimmune thrombocytopenia, and discuss differential diagnosis and possible mechanisms involved in the development of thrombocytopenia during therapy with INF-alpha.