Persistent structural and governance impediments continue to constrain the growth and sustainability of enterprises in Kenya, despite numerous policy interventions. A comprehensive diagnostic framework to systematically identify and analyse these interconnected challenges has been notably absent. This paper develops and presents a novel diagnostic framework designed to systematically identify, categorise, and analyse the root causes of structural and governance challenges within Kenyan enterprises. It aims to move beyond descriptive analysis towards a causal diagnostic tool. The research employs a multi-method design, integrating a systematic review of extant literature with thematic analysis of longitudinal case studies from diverse sectors. The framework was constructed and refined through iterative application to these cases. Analysis reveals that governance deficiencies, particularly in board oversight and transparency, are a primary root cause exacerbating structural weaknesses in access to finance and market linkages. A dominant theme was the misalignment between formal governance structures and informal, culturally embedded business practices. The diagnostic framework successfully elucidates the causal pathways through which governance failures amplify structural constraints. It provides a more nuanced understanding than prior siloed analyses of either governance or structure alone. Enterprise support programmes should integrate governance capacity building with structural interventions. Policymakers are urged to utilise the framework for targeted, evidence-based programme design that addresses root causes rather than symptoms. corporate governance, structural constraints, diagnostic framework, enterprise development, business environment This paper's primary contribution is the introduction of a novel diagnostic framework that explicitly models the causal interplay between governance mechanisms and structural business constraints, offering a new tool for researchers and policymakers.