There are many conditions which are associated with neutropenia, such as infections, chemical and physical agents, and hematopoietic diseases. But ticlopidine-induced neutropenis is rarely reported in Korea. We experienced a case of neutropenia which developed after approximately 1 month of ticlopidine administrarion to a stable angina pectories patient. A 59 year-old woman with stable angina pectoris was placed on ticlopidine. Forty days later, she was admitted for high fevers and shaking chills. On admission, leukocyte count was 900/mm (3) (neutrophil 0/mm (3)), hemoglobin was 11.8g/dl, and platelet count was 440.000/mm (3). After confirming ticlopidine-induced neutropenia by bone marrow aspiration and biopsy, we administated rhG-CSF (neutrogen (r), Choongwae. Co. Korea) at a dose of 3-5ug/kg daily. On the 25th day of treatment, leukocyte count reached 2,890/mm (3). She experienced no adverse effects of rhG-CSF treatment and recorved completely. We assume that the rapid recovery of granulocytes was attributable to rhG-CSF, and we suggest that rhG-CSF should be tried in a patients with ticlopidine-induced neutropenia with depletion of myeloid precursors in the hypocelluar bone marrow.