Purpose:Little is known about the epidemiology of Mondor’s disease. The aim of this study was to analyze the clinical features of Mondor’s disease in an outpatient clinic where primary care physicians are working in Japan, to better understand the epidemiological characteristics of the disease.Patients and methods:The data for consecutive outpatients who were new visitors to the Department of General Medicine in the teaching hospital (Asahikawa Medical University Hospital) at Asahikawa Medical University, Asahikawa, Hokkaido, Japan, between April 2004 and March 2012 were analyzed. Parameters such as age, sex, diagnosis, and clinical presentation were investigated.Results:During the 8-year period covered in this study, six (0.07%) out of 8767 patients were diagnosed as having Mondor’s disease. All of these patients with Mondor’s disease were female, and the mean age was 41 plus or minus 12 years; the overall rate of Mondor’s disease in all female patients involved in this study was 0.12%. The patients complained of pain and a cord-like structure in the anterolateral thoracoabdominal wall. The painful mass had persisted for 1–4 weeks before presenting at the Department of General Medicine and it disappeared within a couple of weeks. Current smoking was significantly higher in the patients with Mondor’s disease than in the age-matched female patients without Mondor’s disease who were also evaluated in this study.Conclusion:These results suggest that a high rate of smoking in middle-aged females may be a characteristic feature of Mondor’s disease. These epidemiological data may be useful in detection of the disease in the primary care setting in Japan.