As the threat of polio grows across the Eastern Mediterranean Region, the Ministry of Public Health launched a national polio immunization campaign to prevent polio regaining a foothold in Lebanon after an absence of 13 years. The campaign aimed to immunize at least 600,000 children under-five years of age against polio over a period of six days. During that campaign, children also received vaccines against measles and rubella as well as vitamin A which strengthened their immune systems. Vaccines were received for free at primary health centers, public and private schools, and from private doctors. Vaccinators also travelled door-to-door and mobile teams visited 1,185 informal settlements nationwide to vaccinate Syrian refugees living there. InfoPro was commissioned by UNICEF to monitor the vaccination process. InfoPro Third Party Monitors visited 73 of the settlements and carried-out two types of independent monitoring:1) In-process monitoring during the immunization campaign: monitors were requested to assess the performance of the vaccinators and to fill a pre-defined general checklist by observing teams working on the ground and 2) Intra-campaign monitoring: monitors visited settlements to check vaccination status of children based on filling another pre-defined checklist and provide an independent evaluation of quality based on finding missed children and reasons for non-vaccination.