The aim of our study was to gain understanding of different types of conflicts on knowledge in the discussions of problem-based learning tutorial groups, and how such conflicts are dealt with. We examined first-year medical and dental students' (N = 33) conflicts on knowledge in four videotaped reporting phase tutorials. A coding scheme was created for analysing verbatim transcripts of 43 conflict episodes in order to find out whether the conflict episodes were about factual or conceptual knowledge and how the students elaborated the knowledge. Conflict episodes were relatively rare (taking up 7.6% of the time) in the videotaped groups. Conflict episodes were more frequently about factual knowledge (58%) than conceptual knowledge (42%), but conflicts on conceptual knowledge lasted longer and were more often elaborated. Elaboration was, however, more frequently done individually than collaboratively. Conflict episodes were generally fairly short (mean duration 28 s). This was due to a lack of thorough argumentation and collaborative elaboration of conflicting ideas. The results suggest that students' skills to bring out differences in each other's conceptual thinking, the depth of argumentation and the use of questions that elicit elaboration need to be improved. Tutors' skills to facilitate the collaborative resolving of conflicts on knowledge call for further study.