The study investigates the factors affecting ICT adoption by SMEs in Nigeria. The structured questionnaire was used to collect data from seventy (70) respondents. The method of analysis is that of correlation coefficient and multiple regressions while the method of estimation is Ordinary Least Squares (OLS) with aid of STATA software. The result indicates that infrastructure is one of the most factors that inhibit ICT adoption by SMEs in Nigeria with highest mean followed by government policies, management support, level of security, maintenance cost skills and training, and investment cost respectively. It is concluded that SMEs in Nigeria have been slow in adopting ICT as they face major constraints such as poor telecommunication infrastructure, limited ICT literacy, inability to integrate ICT into business processes, high costs of ICT equipment, incomplete government regulations for e-commerce, legal and regulatory issues, weak ICT strategies, lack of research and development, excessive reliance on foreign technology and weaknesses in ICT implementation. The study recommends that management should plays an important role in guiding and completing projects relating to ICT adoption, by providing resources for the purchase of the infrastructures required for the new ICT.