I consider two transcendental arguments for realism in the philosophy of science, which are due to Roy Bhaskar (A realist theory of science, 1975) and Nancy Cartwright (The dappled world, 1999). Bhaskar and Cartwright are both influential figures, however there is little discussion of their use of transcendental arguments in the literature. Here I seek to correct this oversight. I begin by describing the role of the transcendental arguments in question, in the context of the broader philosophical theories in which they are embedded, by Bhaskar and Cartwright respectively. I then consider some specific problems that arise for these particular transcendental arguments, in the context of contemporary philosophy of science. I raise two general problems for transcendental arguments for realism and I finish by spelling out what needs to be done to address the criticisms raised in this paper.