The aim of this analysis is to identify the possibility of treating eco-innovation in micro and small enterprises as a factor influencing the energy efficiency of the economy. In order to obtain an answer to such a research question, quantitative research was carried out among Polish enterprises from the SME sector (N = 400). Accordingly, the CATI technique was applied. The selection of enterprises was random and took place in the non-returnable drawing process. The criterion for selecting the sample was the size of enterprises, but in order to ensure the possibility of drawing conclusions based on a sufficiently large research sample, its structure (300 micro and 100 small enterprises) assumed the study of small enterprises in a proportion greater than their actual share in the population of enterprises. As a result of this research, the existence of a relationship between the improvement of the company’s competitive position and its activity in the field of eco-innovation implementation was confirmed. It is shown that the behavior and attitudes of entrepreneurs largely determine the very decisions regarding the use of specific types of eco-innovation, as well as the areas in which they brought about changes influencing the improvement of the competitive position of the surveyed companies. Differences in these decisions can be observed in micro and small companies. This article justifies the notion that the impact of the scale of micro and small companies is important in shaping the energy efficiency of the economy.