This paper investigates what pragmatism can mean to information systems research. It makes a division into three types of pragmatism: Functional, referential and methodological pragmatism. These three kinds of pragmatisms are explained through their different knowledge - action relations. Functional pragmatism is described as -knowledge for action-. Referential pragmatism is described as -knowledge about action-. Methodological pragmatism is described as -knowledge through action-. The paper identifies briefly how different trends in information systems research are related to these three kinds of pragmatism; as e.g. method development, design research, use of action theories, action research.