This article examines constructivism, a paradigm in qualitative research that has been propagated by Egon Guba, Yvonna Lincoln, and Norman Denzin. A distinction is made between whether the basic presuppositions of constructivism are credible compared to those of a competing paradigm and whether constructivism's beliefs are internally consistent. The latter approach, i.e. whether constructivism is internally consistent, is the focus of this article. The issues singled out for discussion are concerned with the constructivist ontology and epistemology. This article shows that constructivism's paradigmatic beliefs are internally in tension.