Nowadays, Blockchain has become one of the most widely used tools in recent years due to its efficiency for various uses, one of them being smart contracts. The main objective is to identify the state of the art of research on Blockchain in Smart Contracts over the last 7 years. A systematic review of the literature was conducted, defining bibliographic sources such as Scopus, Web of Science, Science Direct, IEEE Xplore, EBSCOhost, and ARDI to carry out search strategies, resulting in 13,476 articles. Exclusion filters were applied using the PRISMA Flow Diagram to finally obtain 76 quality articles for review. The results of the SLR indicate that China is one of the countries that contributes the most research on this topic. Additionally, Solidity and Vyper are the most widely used programming languages for developing Blockchain. Interesting findings have been provided that give context to the research conducted on this topic.