The post-marketing surveillance of meropenem (Meropen) for febrile neutropenia (FN) was conducted between July 2010 and June 2012 to evaluate safety and efficacy under actual clinical use. There were 1191 and 1124 evaluable cases for safety and efficacy respectively, of 1207 case cards collected from 180 institutions. In safety analysis, the incidence of adverse drug reactions (ADRs) associated with use of meropenem (including abnormal laboratory findings) was 15.7% (187/1191 cases), and the main ADRs were alanine aminotransferase increased, aspartate aminotransferase increased, blood alkaline phosphatase increased, hepatic function abnormal, and liver disorder, which were similar to these observed in the clinical study for FN or post marketing surveillances of meropenem conducted before. In efficacy analysis, the overall efficacy was 81.8% (919/1124 cases). Also, it was 79.2% (708/894 cases) for hematological malignancy and 91.8% (213/232 cases) for solid cancer. These results confirmed meropenem (Meropen) is one of the well-tolerated and potent antimicrobial agents for febrile neutropenia.