OBJECTIVE： To explore the mode， methods and role of clinical pharmacists providing pharmaceutical care for patients with natural killer/T-cell lymphoma （NK/TL） complicated with diabetes.  METHODS： Clinical pharmacists participated in SMILE chemotherapy plan for a NK/TL patients with diabetes mellitus， evaluated potential chemotherapy risk during first chemotherapy， implemented individual medication monitoring and put forward suggestion. It included insulin injection 4 U， ivgtt， to control the increase of blood glucose induced by dexamethasone； sodium bicarbonate 40 ml， ivgtt， bid to alkalize urine； allopurinol 0.1 g， po， tid to inhibit uric acid； fluid infusion 4 000 ml/d to prevent renal failure； mesna 0.4 g/time to protect urinary passage； monitorring potential allergic reaction and arrest of bone marrow； providing medication education on the application of calcium folinate in SMILE chemotherapy regimen. RESULTS： Physicians adopted the suggestions of clinical pharmacist， and chemotherapy was carried out smoothly. No ADR was found， and patients manifested good medication compliance. CONCLUSIONS： Clinical pharmacists participate in chemotherapy， evaluate potential risk and provide individual medication monitoring， which optimize therapy plan， reduce medication risk and guarantee the safety of drug use.