Objective To investigate the diagnosis and surgical management of Hashimoto's thyroiditis and coexisting disease. Methods The clinical data of 54 patients with Hashimoto's thyroiditis were analyzed retrospectively. Results 25 cases were diagnosed as Hashimoto's disease by clinical physical examination, FNAB and immune antibody assay. Diagnostic treatment with medicine was adopted firstly. Of them 24 cured, one was found coexisting thyroid cancer, and then a radical operation was performed. The other 29 cases had been misdiagnosed as surgical diseases because of atypical features and undergoing thyroidectomy; the diagnosis of Hashimoto's disease had been confirmed by pathology, and some coexistence had been found(hyperthyroidism in 3, thyroid carcinoma in 4, malignant lymphoma in 2, thyroid adenoma in 5). Conclusions Attention should be paid to the atypical Hashimoto's disease. FNAB, immune antibody assay, diagnostic treatment, operative exploration and biopsy would be helpful to make the sound diagnoses of Hashimoto thyroiditis and the disease in coexistence, which ought to be operated on corresopondingly.