Mitochondrial division is mediated by the conserved dynamin-related GTPase DNM1L/DRP1. DNM1L assembles onto the surface of mitochondria and constricts this tubular organelle. Alterations in mitochondrial division are linked to many neurodegenerative diseases. However, the in vivo function of mitochondrial division is poorly understood. In our recent paper, we studied the physiological role of mitochondrial division in postmitotic neurons using the cre-loxP system. We found that the loss of DNM1L resulted in increased oxidative damage in mitochondria, impaired respiration and neurodegeneration in postmitotic neurons. Suggesting a decrease in mitochondrial turnover, mitophagy-related proteins such as LC3, SQSTM1/p62 and ubiqutin accumulated in division-defective mitochondria. These findings suggest that mitochondrial division functions as an important quality control mechanism that suppresses oxidative damage and neurodegeneration in vivo.