This chapter discusses social problems from the perspective of Niklas Luhmann's sociological systems theory. We argue that his theory provides a rich framework to gain relevant insights for the study of social problems. The key element of systems theory is the concept of functionally differentiated society, that is, a heterarchical arrangement of social systems such as the economy, polity, religion, science. Luhmann's theory connects core ideas from both realist and constructionist epistemologies without ending up in inconsistencies or contradictions. The theory gives justice to realism insofar as it takes the systemic nature of social phenomena seriously and it defies simplistic models of causality, steering, planning, and intervention. Systems theory is constructionist insofar as it takes the multiperspectivity of modern society seriously: many social systems construct their own definitions of social problems including underlying causalities and values. The same social problem appears differently from different systems’ perspectives.