PURPOSE: To investigate long-term visual outcome in inferior posterior staphyloma (IPS) in each group classified based on macular complications and to examine the treatment effect for eyes with IPS with choroidal neovascularization (CNV). DESIGN: Prospective clinical cohort study. PARTICIPANTS: We analyzed 56 eyes of 43 consecutive patients with IPS who were followed for 4 years. METHODS: We classified eligible eyes into 3 groups based on baseline findings: eyes without CNV or retinal exudate (no-exudate group), eyes without CNV and with retinal exudate (exudate group), and eyes with CNV (CNV group). We investigated the best-corrected visual acuity (BCVA) and associated parameters for 4 years. RESULTS: BCVA declined during 4 years only in the exudate group (P = .002), whereas it was maintained for 4 years in the no-exudate and CNV groups (P = .53 and .20, respectively). Baseline BCVA was lower in the CNV group than in the exudate group (P = .004); however, the 4-year BCVA was not (P = .84). The 4-year BCVA was associated with baseline BCVA in all groups. Eyes in the CNV group required 9.0 ± 8.7 anti-vascular endothelial growth factor therapy in 4 years. CONCLUSIONS: Better baseline BCVA in eyes with exudative IPS without CNV spontaneously declined in 4 years, whereas worse baseline BCVA in eyes with IPS with CNV did not, probably because of treatment for retinal exudate from CNV. Anti-vascular endothelial growth factor therapy would be effective for long-term maintenance of BCVA in eyes with IPS with CNV, similar to other diseases with CNV.