Objective To investigate the diagnosis and treatment methods based on different stages for plasma cell mastitis (PCM). Methods A total of 46 patients with PCM from September 2010 to January 2014 in Shanghai Xuhui District Dahua Hospital were investigated; different clinical stages of plasma cell mastitis were treated by using different methods including drugs, surgical drainage or surgical removal. Results Different clinical stages of PCM were recovered after treatments based on different stages. Conclusion Treatment methods for plasma cell mastitis should be based on different clinical stages in order to increase cure rate and reduce the recurrence rate of plasma cell mastitis.