<p>To compare the clinical features of acute acquired concomitant esotropia (AACE) between adolescents and adults. The clinical features were stratified by age and analyzed. The adolescent group included patients aged &lt; 18 and the adult group included those aged ≥ 18. Refractive status, the angles of esotropia, angles of deviation at near and far, diplopia, and stereopsis were evaluated. <i>p</i> &lt; 0.05 was considered statistically different. 59 patients were included in the adult group (31 males and 28 females; mean age 29.86 ± 9.64), and 42 patients in the adolescent group (29 males and 13 females; mean age 11.57 ± 3.98). Age was positively correlated with disease duration, fusional function, and distance stereopsis. In contrast, the age was negatively correlated with spherical equivalent-right eye (SE-Right), spherical equivalent-left eye (SE-Left), the angles of deviation at near, and the angles of deviation at distance. The refractive state of different age groups was significantly different (χ² = 17.649, <i>p</i> &lt; 0.001). The angles of esotropia in the adolescent group were significantly larger than the adult group (<i>p</i> &lt; 0.001). No statistically significant difference was observed between the two groups for distance stereopsis (χ² = 2.143, <i>p</i> = 0.143) and near stereopsis (χ² = 0.671, <i>p</i> = 0. 413). AACE has diverse clinical features between the adolescent and adult populations. The adults presented more severe myopia and smaller angles of esotropia compared to the adolescents, which may be related to different pathogenesis and different eye habits.</p><p><i>Trial registration</i>: ChiCTR2100053717. Registered 28 November 2021—Retrospectively registered, <a href="https://www.chictr.org.cn/">https://www.chictr.org.cn/</a>.</p>