Objective To explore the influencing factors of thyroid function recovery in the elderly patients undergoing unilateral thyroid lobectomy. Methods A total of 346 patients receiving unilateral thyroid lobectomy in Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Sciences from June 2020 to June 2022 were enrolled as the study subjects, and they were divided into young and middle-aged group (18-<60 years, n=113) and elderly group (≥60 years, n=233). The postoperative thyroid function recovery was compared between age groups, and the incidence rate of hypothyroidism was counted. The patients with hypothyroidism in the elderly group were included in the hypothyroidism group (n=65) and those with normal thyroid function were selected as the control group (n=168). SPSS 19.0 was used for data analysis. According to the data type, t test, analysis of variance or Chi-square test was used for comparison between groups. Binary logistic regression model was used to analyze the influencing factors of the postoperative thyroid function in the elderly patients undergoing unilateral thyroid lobectomy. Results At two months after surgery, the level of free triiodothyronine (FT3) in the young and middle-aged group was lower than that before surgery, and the level of thyroid stimulating hormone (TSH) was higher than that before surgery, the differences being statistically significant (P<0.05). The two indicators returned to the preoperative levels at six months after surgery. There was no significant change in the level of free thyroxine (FT4) at different time points after surgery as compared before surgery with no statistically significant difference (P>0.05). In the elderly group, at two months, six months, and one year after surgery, the levels of FT3 and FT4 were lower, and the TSH level was higher than those before surgery, the differences being statistically significant (P<0.05). The level of FT4 in the elderly group at each time point after surgery was lower than that in the young and middle-aged group, and the level of FSH before surgery and at each time point after surgery was higher than that in the young and middle-aged group, the differences being statistically significant (P<0.05). The incidence of hypothyroidism at one year after surgery in the elderly group (27.90%) was higher than that in the young and middle-aged group (8.85%) (χ²=4.225, P<0.05). Binary logistic regression analysis suggested that age (OR=2.199,95%CI 1.099-4.401), body mass index (OR=1.793,95%CI 1.275-2.522), preoperative TSH (OR=2.404,95%CI 1.419-4.072), positive thyroid peroxidase antibody (TPOAb) (OR=1.988,95%CI 1.081-3.657) and serum interleukin-6 (IL-6) level (OR=1.624,95%CI 1.232-2.141) were factors affecting postoperative hypothyroidism. Conclusion The elderly patients have a poorer thyroid function recovery after unilateral thyroid lobectomy than the young and middle-aged patients and are more prone to hypothyroidism. Preoperative TSH elevation, positive TPOAb, age, body mass index and serum IL-6 level are factors affecting hypothyroidism in the elderly after unilateral thyroid lobectomy.