Background: Thymoma is often associated with a series of paraneoplastic syndromes. Among them, thymoma-related nephrotic syndrome is much rare.Methods: This retrospective study collected data from patients with thymoma and renal involvement in Xiangya Hospital, Central South University in a period of 5 years to investigate the clinical characteristics of thymoma-associated nephrotic syndrome.Results: Seven patients were studied (age: 51.1±21.4 years old; male/female ratio: 5/2). Among them, thymic pathology revealed 2 cases of type A and 1 case of type B3, myasthenia gravis (MG) was found in 1 out of 7 cases. Renal pathology showed 2 cases of FSGS and 1 case of IgA nephropathy. 2 out of 7 cases who received combined therapy of steroid and immunosuppressive drugs achieved complete remission. Despite 3 out of 7 cases received surgical excision of thymoma, 2 of them experienced treatment failure in nephrotic syndrome.Conclusions: nephrotic syndrome can be associated with thymoma. The FSGS is the most frequent thymoma-associated glomerular lesion in this study. IgA nephropathy may be another pathological type in thymoma-associated NS. Despite after surgical excision, long treatment periods with high dosage of steroid combined with immunosuppressants were needed to achieve complete remission.