Small and Medium Businesses (SMB) have substantial potential to contribute to the growth of an economy through adoption of business related Information Technology. The Agricultural and Food Business (AFB) sector in Oman is dominated by SMBs. Factors influencing the adoption of e-commerce in the AFB sector in Oman were analyzed. The main hypothesis was that scale of the business influenced the adoption of e-commerce. Data were obtained from a random sample (n = 31) of AFBs in Oman and was analyzed using a Probit regression model. The dependent variable was whether the firm had a website, a proxy measure of adoption of e-commerce. The main independent variables were the scale of the business (measured by number of employees) and the scope of the business (international or national) and of variables related to manager's perception of benefits of adopting e-commerce. It was found that 94% of AFBs in Oman used computers and about 52% of those had websites. The R-squared, of the estimated Probit regression model was 0.65. The hypothesis that scale of the business influenced the adoption of e-commerce was not rejected, as the coefficient of the business scale variable was statistically significant (t = 2.5, n = 31). The likelihood of adoption increases with increased scale of the business. On the converse this suggests that the likelihood of adoption of e-commerce by small and medium businesses is lower. Given the importance of small and medium businesses in the development of particularly the AFB sector of Oman, policy maker would have to promote and provide incentives to adopt e-commerce by SMBs.