Background: No single assessment method can successfully evaluate the clinical ability of medical students in psychiatric clerkships; however, few studies have examined the efficacy of multiple assessments, especially in psychiatry. The aim of this study was to examine the relationship among different types of assessments of medical students' clinical ability in psychiatric clerkships and whether it is reasonable to use multiple assessments. Method: A group of 196 students were enrolled during their psychiatric clerkship between September 2008 and May 2009 in Kaohsiung, Taiwan. The mini-clinical evaluation exercise (mini-CEX) and standardized patient (SP)-based test were used to evaluate "does" and "show how" in psychiatric clinical ability. A multiple-choice examination was used to evaluate knowledge of psychiatry. Results: There were statistically significant but weak correlations among the scores on the multiple-choice examination, SP-based test, and overall clinical competence domain on the mini-CEX. Conclusion: A blended assessment composed of a multiple-choice examination, mini-CEX, and SP-based test can evaluate different dimensions of clinical ability. It is reasonable to use multiple methods to assess medical students' competency in psychiatric clerkships.