Weak institutional development and information flows have constrained the extent to which the smallholder farming sector in developing countries can significantly drive growth and poverty reduction. This is despite widely implemented economic liberalisation policies focussing on market efficiency. Farmer organisations are viewed as a potential means of addressing public and private institutional failure but this has frequently been limited by inequalities in access to power and information. This article investigates two issues that have received little research attention to date: what role downward accountability plays in enabling farmer organisations to improve services and markets, and what influences the extent to which downward accountability is achieved. Kenya Tea Development Agency (KTDA), one of the largest farmer organisations in the world (>400,000 farmers) is examined alongside wider literature. Mixed methods were used including key informant interviews, and eight months of participant observation followed by a questionnaire survey. The article concludes that without effective downward accountability farmer organisations can become characterised by institutions and mechanisms that favour elites, restricted weak coordination and regulation, and manipulated information flows. This in turn reduces individuals’ incentives to invest. If farmer organisations are to realise their potential as a means of enabling the smallholder sector to significantly contribute to economic growth and poverty reduction, policy and research needs to address key factors which influence accountability including: how to ensure initial processes in formation of farmer organisations establish appropriate structures and rules; strong state regulation to enhance corporate accountability; transparent information provision regarding actions of farmer organisation leaders; and the role independent non-government organisations can play. Consequently attention needs to focus on developing means of legitimising rights, building poor people's capacity to challenge exclusion, and moving from rights to obligations regarding information provision.