Introduction: The medial articular surface of dried clavicles have been studied to evaluate sex and age in many races. This morphological investigation in Thai population has never been reported. This study aimed to classify the clavicular medial surfaces and to provide their incidences. Materials and Methods: 454 dried clavicles (254 males and 200 females), averaged age (60.69±14.36 years), from KKU Osteological Collection Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, were systemically investigated for types and incidence of their medial articular surface. Results: The showed that medial articular surfaces of Northeastern-Thais were classified into 6 types: smooth (type 1 = 7.71%), slight granulation (type 2 = 16.74%), coarse granulation (type 3 = 41.63%), nodule formation (type 4 = 1.54%), undulating (type 5 = 24.89%), and degeneration (type 6 = 7.49%), respectively. Conclusion: These basic data can be used for teaching the medical and paramedical students and also might be applied in forensic sciences especially identifying of Northeastern – Thai clavicle remains.