In this study we made a comparative examination of the achievement level of clinical reasoning ability of physical therapy students in a problem-based learning (PBL) tutorial, and its inter-group disparity. [Subjects and Method] Thirty-six 3rd year students at a 4-year physical therapy vocational college were given a PBL tutorial, and we performed an assessment of students' self-assessment and teachers' evaluation of each group of students with respect to the clinical reasoning achievement level from 6 items constituting it: overall understanding, use of information, interpretation and integration of assessment, identification of problem points, prognosis, and program. [Results] From both the students' self-assessments and teachers' evaluations, the items of conception of problem points and prognosis had a low assessment compared to the other items. In the teachers' evaluations, for all groups overall understanding and interpretation and integration of assessment had a comparatively high assessment, and in the students' assessments, for all groups use of information and overall understanding had a comparatively high assessment. In general assessment of clinical reasoning, significant differences were not seen among teachers' assessments for groups comprised of 7 or 8 students. [Conclusion] In group study, a comparatively high level of clinical reasoning ability was achieved. Even with minimal intervention of tutors differences in ability were not seen, and an uniform level of learning effect was achieved.