Background <p>Hypothyroidism is a significantly harmful condition that severely affects work and daily life. Currently, there is a lack of large-scale investigations into the treatment control status in China. This study aimed to combine a large sample of patients with hypothyroidism in the Guangzhou area to analyze hypothyroidism control rates.</p> Methods <p>A cross-sectional survey was conducted at six tertiary A-grade hospitals in Guangzhou city. On-site questionnaire surveys were administered to randomly sampled outpatients with hypothyroidism (<i>n</i> = 1516) to collect cross-sectional data. The collected data were analyzed to summarize the current status of hypothyroidism control, the composition of hypothyroidism etiology, complications, and their correlation with hypothyroidism control rates in Guangzhou.</p> Results <p>The overall control rate of patients with hypothyroidism (with TSH level &lt; 4 mU/L as the standard) was 59.4% (49.2% in males and 61.2% in females). There was a significant correlation between TSH control rate and sex and education. In addition, the TSH control rate after treatment was higher in those aged &lt; 35 years and during the mid-term of pregnancy in pregnant women with hypothyroidism. The control rate of TSH was closely associated with abnormal liver function, menstrual disorders, dysmenorrhea, and sleep disorders. Finally, a history of thyroid surgery, type of thyroid surgery, and presence of Hashimoto’s thyroiditis were correlated with the control rate of TSH.</p> Conclusion <p>The control rate in patients with hypothyroidism was relatively low in Guangzhou area. Patients with hypothyroidism and clinical characteristics closely associated with poor hypothyroidism control should receive special attention.</p> Clinical trial number <p>Not applicable.</p>