SMEs are considered the backbone of the Sri Lankan economy, and e-commerce can be viewed as a ladder for business growth. Therefore, it is important for SMEs to adopt e-commerce. Studies show that Sri Lankan SMEs do not use e-commerce to its full potential. Therefore, before adopting e-commerce-based tools and technologies, it is essential for SMEs to consider their readiness to adopt e-commerce. The research is conducted through a systematic literature review using the PRISMA framework. This study has identified several main factors affecting e-commerce readiness: availability of knowledge and skills, human resource availability and compatibility, management influence, perceived benefits, finance management, organizational culture, availability of IT infrastructure, compatibility of business processes, and organizational governance. The availability of IT infrastructure was the most considered factor, where organizational governance was the least considered factor compared to other factors, when assessing e-commerce readiness and adoption.