Throughout the years, entrepreneurs play an important role for the growth and development of the economy in a country. The ability to open and expand businesses depend on the efforts of entrepreneurs to utilize their skills to satisfy customers. The open ‘innovation’ term was introduced as a paradigm to open for opportunities and ideas from outside of organization in order to generate a better innovation. The purpose of this research is to describe the relation between open innovation and business performance at PT. Sinar Logam Medan and to reveal whether it is the factor that cause performance issue in the company. The data were collected by using descriptive and correlative research methods. The results of validity test on variable X and Y were valid because the value were over than Rtable standard of value. It was the same with reliability test, the results were reliable because they were over than 0.6. By using Kolmogorov test, the data of variable X and Y were normal because the value was over than 0.05. From the correlation test, it can be known that coefficient of correlation was in 0.954, which means that the level of relationship was strong. From the test of determination, the coefficient of determination was 90.9% which means that variable X had impact on variable Y. The alternative hypothesis was accepted because, while the Ztable with margin of error 5% is 1.96, the calculated Zcount was 9.49. From those results, it can be stated that open innovation had impact towards business performance at PT. Sinar Logam Medan.