This paper provides empirical evidence on the effects of fiscal decentralisation on public service delivery in devolved systems of government in Kenya. A qualitative study interviewed 126 respondents and held two focus group discussions with key stakeholders from within two of Kenya’s 47 counties: Kiambu and Nairobi City. The paper focuses on key elements of fiscal decentralisation, namely: expenditure responsibilities, revenue autonomy and borrowing powers. Public service delivery was examined using affordability as a key measure of the quality of services. Results show that fiscal decentralisation did not necessarily lead to more affordable public services as there were significant contextual factors such as corruption, legal structures, cultural values, belief systems, pressure to conform and change agents that moderated this relationship. Corruption made public services less affordable in both counties, while Nairobi Metropolitan Services emerged as a change agent that improved the affordability of specific public services within Nairobi City county. The paper outlines a conceptual framework for further research into implementation of fiscal decentralisation in Kenya and elsewhere, especially in Africa, and calls for more qualitative studies, especially longitudinal studies, case studies and ethnographic approaches to enrich knowledge in this field.