Nilotinib is a selective tyrosine kinase inhibitor for the treatment of Philadelphia chromosome-positive leukemias. An elevation of the pancreatic enzyme level is one of the major adverse events associated with nilotinib, but whether or not nilotinib induces symptomatic pancreatitis remains to be elucidated. The cases of two chronic myeloid leukemia patients treated with nilotinib who developed symptomatic acute pancreatitis on the third and fifth day of nilotinib administration are herein presented. Since both patients had no other etiologies for pancreatitis, nilotinib was considered to be the causal agent. The withdrawal of nilotinib resulted in a prompt recovery. These cases underline the importance of recognizing pancreatitis as a possible adverse event associated with nilotinib.