The Kingdom of Saudi Arabia will review its pioneering experience in Hajj seasons, as it is a unique experience in managing more than 3 million pilgrims in a specific geographical and time range, during the Fourth International Conference for Mass Gatherings Medicine organized by the Ministry of Health, under the patronage of the Custodian of the Two Holy Mosques King Salman bin Abdulaziz Al Saud, which will be held in Jeddah from 10 - 13 December 2019. The Kingdom is a leading reference in the field of crowd health and management and has distinguished experiences in this field, which were praised by many international health organizations. The Conference, which will witness the participation of more than 30 countries, will address a number of topics related to crowd management experiences, such as developing systems, financing mechanisms, health awareness, education, health security and e-health.