This study aims to improve the evidence base for programmes and policies seeking to facilitate labour mobility for development within the ECOWAS region. The study is based on secondary data collected from available administrative data sources, surveys and censuses in all 15 ECOWAS countries and is complemented by interviews with key informants, such as policymakers, immigration officials and statistical offices. The study identified data sources and compared existing data on labour migration, as well as analysed the structure of labour markets and labour migration. It also examined obstacles faced in the implementation of the Protocol on Free Movement of Persons, Right of Residence and Establishment in each ECOWAS country. The study highlights the absence of comprehensive, reliable and accurate data on migration and labour markets as a major obstacle to the facilitation of labour mobility. In all ECOWAS countries, there were no functional existing labour market information systems. Although there has been gradual implementation of the Free Movement Protocol in ECOWAS countries at the national level, several obstacles remain in this process. Neither the second nor the third phases of implementation of the Protocol have led to free rights of residence or establishment in Member States, largely as a result of concerns about unauthorized migration. The study calls for building the capacity of national institutions charged with migration and labour mobility data collection and the harmonization of migration and labour market related concepts and definitions. It also advocates for conducting periodic labour market and migration surveys to ascertain labour needs and supply. There is also the need to prioritize the harmonization of travel documents and migration policies in the region.