Health professionals use critical thinking, a key problem solving skill, for clinical reasoning which is defined as the use of knowledge and reflective inquiry to diagnose a clinical problem. Teaching these skills in traditional settings with growing class sizes is challenging, and students increasingly expect learning that is flexible and interactive. This paper describes the implementation and evaluation of a blended method for teaching clinical reasoning using a wiki. Groups of undergraduate physiotherapy students presented a patient case to their peers in class and on a wiki. Evaluation included student surveys, focus groups, and online participation. Students were actively involved in the wiki (mean contribution of 21.0 web pages (IQR 7.5-34.5). Most students (74%) agreed the inclass sessions were valuable, compared to 48% for the wiki. From the educator's perspective, the wiki facilitated collaboration, ensuring demonstrated reasoning skills in class. Combining wiki with in-class activities enhances student collaboration and learning of critical thinking skills. (Contains 1 figure and 3 tables.)