Purpose – The application of knowledge management (KM) is critical to public sector firm as it is to private sector firm. However, despite its significance, the academic enquiry of KM in public sector is at its nascent stage. This forms the motivation of the present work; this paper aims to analyze and understand the intricate relationship between KM processes and public sector firm performance in terms of operational, quality and innovation performance. Design/methodology/approach – A comprehensive KM processes–performance framework consisting of seven constructs (four constructs of KM processes and three constructs of KM performance) and their underlying factors was developed through an extensive literature review. The employee perceptions of these seven constructs were captured on a five-point Likert scale using a country-wide survey in the UAE public sector. The 270 valid responses captured were then used to first validate the KM framework and then test the hypothesized relationships between KM processes and KM performance. Findings – The findings show that all four KM processes (knowledge creation, knowledge capture and storage, knowledge sharing and knowledge application and use) had a positive and significant impact on operational, quality and innovation performance of public sector in the UAE. Research limitations/implications – The findings confirm the validity and reliability of all the seven constructs and their underlying factors and the assessment framework. Overall, this study fills a gap in the literature about applying/implementing a KM framework for the public sector and therefore significantly contributes toward the theoretical advancement of the field. However, the study does acknowledge the use of perceptual measures of individual employees as a limitation instead of more objective measures to capture the impact KM processes on KM performance. Practical implications – The strong and significant impact of KM processes on firm performance is expected to provide the impetus for practitioners and policymakers to implement and leverage from KM processes and improve firm performance in the public sector. Originality/value – A comprehensive development, validation and assessment of a KM framework for the public sector has not been attempted previously anywhere, let alone UAE, and hence constitutes the novelty of this work.