ObjectiveTo use real-world data from a large sample of papillary thyroid microcarcinoma (PTMC) in the SEER database to investigate the impact of delayed treatment on survival outcomes. MethodsA total of 40 761 patients with PTMC eligible for the study from the SEER database of the National Cancer Institute of the United States during 2000–2019 were selected as the study objects and divided into 3 groups according to the different delayed treatment time (0, 0–6 months, >6 months). Kaplan-Meir method was used to plot the survival curve and calculate 5-year cumulative disease-specific survival (DSS) rate and overall survival (OS) rate. Cox proportional hazard regression model was used to analyze the relationship between delayed treatment time, DSS and OS in PTMC patients and the influencing factors of prognosis. ResultsAmong the 40 761 patients, 7 575 (18.58%) were males and 33 186 (81.42%) were females, most of whom were females. The patients ranged in age from 3 to 97 years old [ (51.1±13.9) years old], of which 24 043 (58.99%) were <55 years old and 16 718 (41.01%) were ≥55 years old. Received treatment immediately after diagnosis in 30 823 patients (75.62%), 9 734 patients (23.88%) received treatment within 6 months after diagnosis, 204 patients (0.50%) received treatment 6 months after diagnosis. There were significant differences in age, sex, race, lymph node stage, radiotherapy, surgical method, number of lesions and invasion of thyroid capsule among the 3 groups (P< 0.001). The survival analysis results of the 3 groups showed that the delayed treatment time had no effect on DSS and OS of PTMC patients (P>0.05). The multivariate Cox proportional hazard regression model analysis results showed that the patient’s age ≥55 years old, male, married, lymph node metastasis, radiotherapy, total thyroidectomy and thyroid capsule invasion were the risk factors affecting DSS and OS in PTMC patients (P<0.05), while delayed treatment was not risk factors for DSS and OS in PTMC patients (P>0.05). ConclusionDelayed treatment is not an independent risk factor for DSS and OS in patients with PTMC, and active monitoring is a safe alternative to surgery for some PTMCS.