The aim of this retrospective study was to evaluate the toxicity profiles of dasatinib in patients with Philadelphia chromosome positive chronic myeloid leukemia (CML) or acute lymphatic leukemia (ALL) who were intolerant to imatinib, and who had been enrolled in our previous clinical trials to evaluate efficacy of dasatinib in patients resistant or tolerant to imatinib therapy. Twenty-four patients with CML and four with ALL were enrolled in the clinical studies to evaluate the efficacy according to the eligibility criteria related to intolerance to imatinib therapy. The toxicities reported during imatinib therapy were non-hematological toxicities in 23 patients and hematological toxicities in six patients. Patients were administered dasatinib 50-70 mg BID or 100 mg QD. Cross intolerance was observed in four patients who showed hematological toxicity after dasatinib treatment. However, it was possible to successfully continue therapy with only temporary interruption. No cross intolerance in non-hematological toxicity was found with the exception of one patient who showed cross intolerance, which did not result in treatment interruption. Dasatinib can be safely administered to imatinib-intolerant CML or Ph-positive ALL patients.