This study develops a theory of how human resource management systems contribute to the performance of small businesses. Based on theories from the field of strategic human resource management and small business performance, I argue that high involvement human resource management systems will be positively related to the performance of small businesses above and beyond known drivers of small business performance. A set of moderating variables for this relationship is also presented. I conclude by outlining a set of hypothesis and methods for testing the relationship between human resource management and performance in small businesses.