Purpose: The paper aims to investigate existing research in factors impacting organic food purchase with special reference to eco-labels and identify the relative influence of various determinants. Design/methodology/approach: A conceptual framework is proposed of organic food buying behaviour after analysing a sample of 154,072 consumers reported in 91 research studies from 2001–2020. The factors are categorised into four categories on the basis of relatedness. In addition, the factors were analysed based on time, region and national economic status. Findings: The impact of consumer psychographics, socio-demographic and product-related factor categories were found to be more pronounced compared to supply-related factor category. The results show that among individual factors like health concern, environment concern, knowledge and awareness, eco-labels and price followed by trust in organic food are the most important factors in organic food purchase. The findings suggest that eco-labels increase trust in organic food by reducing information asymmetry in consumers. However, there were differences in perception and factors importance between high-income economies and emerging economies. Originality/value: The study is unique, as it analyses secondary research based on criteria of high-income economies and emerging economies. The conceptual framework can also be incorporated further into different cognitive models like the theory of planned behaviour. © 2020, Emerald Publishing Limited.