Objective To analyze the risk factors associated with hypoparathyroidism (HP) after thyroidectomy. Methods The clinical data of 118 patients with thyroidectomy were reviewed in Ruijin Hospital including parathyroid hormone (PTH) in serum before and after surgery from May 2018 to July 2018. Risk factors associated with postoperative HP were analyzed by multivariate Logistic regression models. Results The incidence of postoperative HP in this study was 17.80% including 2 cases with permanent HP. PTH in serum of 2 cases with permanent HP was 0.049 6 pg/L, 0.008 2 pg/L, 0.013 8 pg/L and those of 19 cases with temporary HP was 0.047 9 pg/L, 0.021 7 pg/L, 0.033 2 pg/L preoperative, postoperative 1 d and 180 d later respectively. Univariate analysis showed that HP was related with tumor N₁ stage, Hashimoto thyroiditis, lymph node dissection, parathyroidectomy, without use of nano-carbon tracer and tumor diameter (P<0.05). However, HP was not related with gender, age, body mass index, hypertension, smoking, drinking, and pathological type (P>0.05). It was shown by multivariate analysis that Hashimoto thyroiditis, tumor N₁ stage, tumor diameter 4 cm and more, lymph node dissection, parathyroidectomy, without use of nano-carbon tracer were independent risk factors for HP. Conclusions The patients with HP after total thyroidectomy were associated with tumor N₁ stage, Hashimoto thyroiditis, tumor diameter 4 cm and more, lymphatic dissection, parathyroidectomy, and without use of nano-carbon tracer which would be the risk factors of HP.