Pastoralism is globally recognized as the backbone of the economy in the vast arid and semi-arid rangelands. Despite its enormous economic contribution, the system is facing a myriad of challenges, among them, land use and land tenure changes, resulting in diminished grazing land. Accompanying such changes is the conversion of traditional grazing lands into other uses such as settlements, with urbanization being one of the key drivers of pastoral system dynamics. Understanding such dynamics in the face of compounding factors such as frequent droughts linked to climate change is key in guiding policy formulation and interventions aimed at achieving a sustainable pastoral production system. This study investigated factors determining migration and settlement of pastoralists in Nairobi City of Kenya. Data was collected through a snowball sampling approach using semi-structured household questionnaires, focus group discussions (FGDs) and key informant interviews (KIIs) in five Sub-counties of Nairobi City County. A total of 144 household interviews, 6 FGDs and 16 KIIs were conducted to elucidate drivers of urban pastoralism, opportunities and challenges encountered by pastoralists in the city. A binary logistic regression model was used to analyse the determinants of their migration. Results show that search for pasture and water resources, and alternative markets especially during droughts, are the main reasons for pastoralists’ migration to the city. In addition, educated herders were found to be more likely to migrate to the city as they pursue wage employment. Whereas these findings revealed that migration to the city exposes pastoralists to diverse livelihood opportunities, they are equally faced by a number of challenges - mainly road accidents involving livestock, frequent land displacements to pave way for development of real estates, and livestock poisoning from sewage and garbage wastes. There is a need for policy and regulatory interventions to recognize pastoralism alongside other forms of urban farming and addressing challenges facing sustainable pastoral production.