The study evaluated the effectiveness of binnasal occlusion (BNO) as a non-invasive treatment for acute acquired concomitant esotropia (AACE) in 32 patients who underwent it for at least 6 months. BNO significantly reduced ocular deviation: median deviation at near decreased from 25.00 PD (IQR 20.00–30.00) to 17.50 PD (IQR 5.50–33.75) ( P = 0.002) and at distance from 30.00 PD (IQR 21.25–40.00) to 5.25–35.00 PD (P < 0.001). Diplopia resolved in 50% of patients (P < 0.001) and binocular function improved (P = 0.019). Patients were divided into cured (orthophoria), effective (≥ 10 PD improvement) and ineffective groups. Smaller baseline deviations and shorter disease duration were associated with better outcomes in univariate analysis, but were not independent predictors in multivariate analysis. BNO is a promising non-invasive method, especially for minor deviations and early treatment, but a control group is lacking, so randomized studies are needed.