The paper is concerned with research into the relationship between human capital and innovation in small and medium-sized enterprises (SMEs) in Poland. The authors describe the results of surveys conducted on a random sample of SMEs, 1,308 in 2007 and 1,346 in 2009. The surveys showed that human capital has a direct influence on innovation in small and medium-sized enterprises. The greater the human capital stock, the more often companies become involved in innovative projects by introducing new products and services, making major modifications to the existing range of products and services, changing the way in which they are organized, introducing new methods for providing services to customers, modifying technology, entering new markets and changing the ways of distributing products. An increase in human capital leads to an increase in internet usage and the popularity of online banking services, in addition to a higher percentage of companies with patents, licenses, registered trademarks and quality certificates, the authors say. They conclude by stating that the results of their research can be applied in economic policy and the management of human resources in small and medium-sized enterprises.