Small and medium-sized enterprises (SMEs) represent the main source of employment in both developed and developing countries. The need to enter global markets and intense competition have made these types of companies increasingly rely on Information and Communication Technology (ICT) to take advantage of its substantial benefits. The vast majority of previous research focuses more on the adoption of ICT in large organizations and does not take SMEs into account in their studies due to their limited resources managed by these types of companies, and this makes the adoption process ICT in this business sector is considerably different. The purpose of this research is to review the literature on the adoption of ICT in SMEs, which includes empirical research and case studies, in order to analyze the internal and external problems that affect their adoption process. This research will help the different parties involved in the ICT adoption process.