Purpose: To investigate whether it is safe to use leucogen tablets 60 mg three times per day (180 mg for a day) and whether this regimen could reduce the incidence of febrile neutropenia caused by chemotherapy. Methods: This prospectively designed study focused on the safety and effectiveness of leucogen tablets 60mg three times per day for a group of cancer patients during chemotherapy for mainly lung or gastric cancers. The tablets were administered from 5 days before until the termination of chemotherapy. Neutropenia and other healthcare encounters were defined as events and occurrence was estimated for comparison. Results: We identified 39 patients receiving leucogen tablets 60mg three times per day, including 11 with gastric, 12 with lung and 16 with other sites of cancer. The mean age was 65 (29-75) years and there were 27 male and 12 female patients. The mean duration of leucogen tablets intake was 59 days. Eighteen patients were treated with taxane-based, 4 with irinotecan-based and 17 with other chemotherapy. The incidence of febrile neutropenia was 0%. Twelve patients were found severe neutropenia (grade III/IV), and the duration of severe neutropenia (grade III/IV) was 5 days. Treatment-emergent adverse events were attributable to complications of myelosuppressive chemotherapy or the primary disease (i.e., alopecia, nausea, asthenia, neutropenia, and severe hepatic renal dysfunction). No chemotherapy was delayed and no treatment related death was observed. Conclusions: This study suggested that leucogen tablets 60mg three times per day (180mg for a day) are safe and could be effective for preventing febrile neutropenia in patients with chemotherapy.