11th Asian Congress of Neurological Surgeons (ACNS) 2016 in conjunction with the 21st Annual Scientific Meeting of Indonesian Society of Neurological Surgeons (PERSPEBSI), March 8th – 12th 2016, Surabaya, Indonesia Author(s): Abdul Hafid Bajamal, M.D. Congress President; Asra Al Fauzi, M.D., Congress Secretary General Information: The 11th ACNS in conjunction with the 21st PERSPEBSI meeting was held from March 8th – 12th, 2016. There were 464 registered delegates and invited experts attended the conference: 228 Indonesian delegates and 236 delegates from 42 countries: Australia, Bangladesh, Bhutan, Bosnia Herzegovina, Brazil, Canada , China, Czech Republic, France, Germany, Hong Kong, India, Iran, Iraq, Ireland, Italy, Japan, Kazakhstan, Malaysia, Myanmar, Nepal, Netherland, Nigeria, Oman, Pakistan, Philippines, Portugal, Romania, Russia, Saudi Arabia, Singapore, South Africa, South Korea, Spain, Taiwan, Thailand, Turkey, UK, Ukraine, USA, Uzbekistan and Vietnam.