Objective To explore teaching effects of case-based learning (CBL) in abdominal physical examination in diagnostics. Methods Among 83 undergraduates in grade 2007 and in major of 8-year clinical medicine were randomly divided into two groups. Under the same conditions, 41 in the CBL group were taught with CBL method, while the other 42 in the control group were taught with traditional teaching method. Their scores in standard patient (SP) practice assessment of abdominal physical examination, examination of abnormal abdominal signs, ability to analyze and write medical records, and right answers to abdominal examination in final exam were compared. Meanwhile, questionnaire surveys were distributed to them after class. Results There was no significant difference between the two groups in the scores of SP practice assessment or medical record writing and analyzing, but the CBL group was obviously superior to the control group in the tests of abnormal abdominal signs and the right answers to abdominal examination in final exam (Plt;0.05). The questionnaire surveys revealed that the CBL group obviously scored higher in the following 3 items: increase the learning interest and commitment, strengthen the ability to analyze and solve problems, and improve the ability to combine theory and practice (Plt;0.05). Conclusion CBL method has an obvious advantage to improve the teaching quality in abdominal physical examination in diagnostics.