We report the long-term surgical results of augmented lateral rectus muscle (LR) recession for dissociated horizontal deviation (DHD) without concomitant exotropia (XT) or esotropia (ET). This retrospective review included patients with DHD without XT or ET who underwent augmented LR recession and were followed-up for ≥12 months. Each patient's medical records were evaluated to identify their demographics, preoperative angle of deviation, surgical procedure, success rate, and reoperation rate. A total of 11 patients with DHD were included (median patient age at surgery, 6 years; interquartile range [IQR], 5 to 10 years). Four patients (36.4%) had a history of infantile ET while three patients (27.3%) had a history of unilateral cataract surgery for congenital cataract. The median preoperative angle of DHD in the unilateral eye was 20 prism diopters (PD) (IQR, 15 to 25 PD). The median amount of LR recession was 8.0 mm (IQR, 7.5 to 8.0 mm). Three patients (27.3%) underwent simultaneous surgery for dissociated vertical deviation. At the final examination after a median follow-up period of 32 months (IQR, 24 to 58 months), 10 patients (91%) showed successful alignment. The long-term successful alignment rate after augmented LR recession for DHD was good; thus, application of this technique is appropriate in patients with DHD.