Purpose: To evaluate the effect of surgical posterior scleral reinforcement in extremely myopic patients (axial length >= 30 mm) with myopic foveoschisis. Methods: The retrospective interventional case series study included patients with an axial length >= 30 mm, posterior scleral staphyloma, and myopic foveoschisis, who were treated either by posterior scleral reinforcement and 23-gauge 3-port pars plana vitrectomy (posterior scleral reinforcement group) or by vitrectomy (vitrectomy group) alone. All eyes additionally underwent cataract surgery. Results: The study included 28 patients (28 eyes) with no significant (all P > 0.05) difference between the posterior scleral reinforcement group (n = 14) and the vitrectomy group (n = 14) in age, refractive error, axial length, and preoperative best-corrected visual acuity (BCVA). In addition to posterior scleral staphyloma and foveoschisis, a macular hole, a macular hole-associated retinal detachment, and a macular detachment without macular hole were present in three eyes, five eyes, and one eye, respectively in the study group and in three eyes, three eyes, and six eyes, respectively in the control group > In the study group, BCVA was significantly better after surgery than at baseline (P = 0.005) with an improvement in BCVA in 13 eyes, whereas BCVA was unchanged in 1 eye. In the control group, BCVA at baseline and at the end of follow-up did not differ significantly (P = 0.22). Gain in BCVA was marginally significantly higher in the study group than that in the control group (improvement by 0.69 +/- 0.76 logMAR vs. 0.19 +/- 0.54 logMAR; P = 0.05). The number of eyes with any improvement in BCVA (13 [93%] eyes vs. 11 [79%] eyes; P = 0.289) did not differ between both groups; an improvement in BCVA by more than 2 lines (10 [71%] eyes vs. 3 [21%] eyes; P = 0.009) was significantly higher in the study group than that in the control group > Anatomical success (defined as closure of macular holes and collapse of the foveoschisis) was achieved earlier in the study group (3.7 +/- 3.2 months vs. 6.2 +/- 3.0 months; P = 0.04). Conclusion: Posterior scleral reinforcement in association with vitrectomy, as compared with vitrectomy alone, was associated with a higher improvement in visual acuity in extremely myopic eyes with foveoschisis.