Business value is a key concept in agile software development approaches. This paper presents results of a systematic review of literature on how business value is created by agile projects. We found that with very few exceptions, most published studies take the concept of business value for granted and do not state what it means in general as well as in the specific study context. We could find no study which clearly indicates how exactly individual agile practices or groups of those create value and keep accumulating it over time. The key implication for research is that we have an incentive to pursue the study of value creation in agile project by deploying empirical research methods.