Constructive controversies, where team members discuss their different opinions openly and politely, can stimulate interprofessional learning (IPL): the learning that occurs in the interactions between two or more different professions. However, in science-based controversies where members compete to be the expert learning becomes complicated. This paper constructs a model for a procedure of a science-based controversy and describes the conditions for IPL in such a setting. The basis for the model is an empirical study. Firstly, we describe how constructive controversies are conceptualised in the literature. We include literature on dialogic teaching and learning. Secondly, we describe how science-based controversies are conceptualised. Thirdly, we present the empirical study. Fourthly, we construct the model which focuses on mental health care professionals but is also applicable to other professionals. The findings suggest a model with three contextual factors which are connected to the use of power strategies and learning strategies. The model gives ideas for educators on why and how to use science-based controversies to facilitate IPL in teamwork. Indirectly a theory is introduced of how to strengthen IPL through controversies. The model is relevant in teaching how controversies which often concern what is best for the users/patients can be handled constructively.