The purpose of this study was to develop a conceptual framework for studying E-marketing adoption among small businesses in Kenya. The specific objective was to review existing information systems adoption theories and models within the information systems literature both at firm level and individual level since small businesses are headed by Individual who acts as the key decision maker. The researcher compared theories at both individual and organization level in order to identify theories and models appropriate for small business adoption studies. Research publications from peer reviewed journals were the source of the secondary data used in this study. The review found that among the theories that has been widely used include Technology Organization and Environment framework and Diffusion of Innovation theory either individually in combination. The study equally found that limited studies have investigated information systems adoption within the lenses of Institutional theory either individually or combined with other theories, yet organizational decisions are driven not only by rational goals of efficiency, but also by institutional environments which include social factors and legitimacy concerns. The researcher was of the opinion that the neo-institution theory combined with selected constructs from DOI and TOE framework would serve as a relevant integrated model for studying small business since it integrates both models/theories fronting the rational goals of efficiency as well as institutional environments.