We hosted the 1st. Conference on Morbidity & Mortality in Neurosurgery (CMMNS) in Toyama on Saturday, February 3, 2018. This was the first conference to intensively discuss and share the knowledge on the morbidity and mortality in daily neurosurgical practice in Japan, and is founded by Prof. Kiyohiro Houkin, Prof. Akio Morita, and me. We were very glad and honored to welcome many neurosurgeons who are interested in this field to Toyama.