Purpose To evaluate the impact of cataract surgery on subfoveal choroidal thickness and central retinal thickness in the elderly. Design Prospective observational case series. Methods This cohort study included 29 eyes of 29 patients with senile cataract, but no previous ocular surgery or other ocular abnormality. All 29 eyes received standard surgery by phacoemulsification and intraocular lens implantation. Subfoveal choroidal thickness and central retinal thickness were measured at baseline and 1, 3, and 6 months postoperatively by spectral-domain optical coherence tomography. Multiple regression analysis was conducted to identify predictors of larger changes in subfoveal choroidal thickness, including sex, age, baseline choroidal thickness, axial length, refractive status before surgery, and duration of surgery. Results The 29 patients with senile cataract received cataract surgery without complication. Mean subfoveal choroidal thickness was 193.8, 208.9, 210.2, and 209.3 μm at baseline and at postoperative 1, 3, and 6 months, respectively, with a statistically significant increase after surgery (repeated-measures ANOVA; P < .0001). In 20 eyes (69.0%), subfoveal choroidal thickness remained high even 6 months after surgery. Multiple regression analysis revealed that male sex (P = .014) and thicker baseline choroid (P = .0048) predicted larger increases in subfoveal choroidal thickness. In contrast, the tendency of transient increase in central retinal thickness was not statistically significant. Conclusion Most elderly patients with senile cataracts are expected to maintain increased subfoveal choroidal thickness for at least 6 months after cataract surgery.