Active surveillance (AS) of low-risk papillary thyroid microcarcinoma (PTMC; T1aN0M0) in adults was initiated in 1993 at Kuma Hospital (Kobe, Japan) and in 1995 at the Cancer Institute Hospital (Tokyo, Japan). Since then, numerous studies from various countries have reported favorable outcomes for patients managed with AS. Notably, no cases of thyroid carcinoma-related death have been reported among patients who have undergone AS. Young age has been identified as a predictor of high tumor growth activity; however, previous studies have shown that young adult patients may still be suitable candidates for AS. Although surgery for PTMC is not technically complex, it carries risks, even when performed by experienced thyroid surgeons, including permanent recurrent laryngeal nerve paralysis and hypoparathyroidism. No significant difference in prognosis has been observed between patients managed with AS and those who undergo immediate surgery (IS). Some patients initially on AS later opt for conversion surgery (CS) for various reasons. Importantly, the postoperative prognosis and incidence of unfavorable events in patients undergoing CS do not differ significantly from those in patients undergoing IS. However, the overall incidence of unfavorable events has been reported to be higher among patients who initially chose IS than among those who began with AS. Patients managed with AS have demonstrated better physical quality of life (QOL) than those who underwent IS. Although findings on mental QOL have been inconsistent, this may depend on the attitudes and approach of the attending clinicians. Presently, AS is considered an excellent initial management strategy for patients with PTMC.