This article examines the concept of probabilistic determinism, a notion usually invoked in analytical behavioral literature in discussion of the determinism. First, we examine some general features of probabilistic determinism in contrast to the conception of absolute determinism. It is argued that there seems to be no significant differences between these types of determinism. Moreover, it is discussed some consequences for this inference to deterministic interpretations of the Behavior Analysis's philosophical commitments. Thirdly, concepts of epistemological and ontological indeterminism are examined taking aim at criticizing some canonical conceptions of the subject. Finally, it is suggested that a reflection on the nature of behavior in the Behavior Analysis can shed some light on the question of determination and indeterminacy of behavior.