We describe a case of serous retinal detachment (SRD) with ciliochoroidal detachment (CCD) that persisted for 2 years and 7 months after minimally invasive glaucoma surgery (MIGS). A 71-year-old woman with primary open-angle glaucoma and cataracts had a central corneal thickness of 489 μm/492 μm and an ocular axis length of 24.05 mm/24.30 mm. She underwent phacoemulsification and intraocular lens implantation in the right eye (OD), along with goniosynechialysis and microhook ab interno trabeculotomy. Postoperative intraocular pressure was 4-6 mmHg in the OD. Five months later, SRD was observed temporally and inferiorly to the macula, with increased choroidal thickness. Best-corrected visual acuity at 5 months was (1.2)/(1.2) (right eye [OD]/left eye [OS]), and intraocular pressure was 6 mmHg/13 mmHg. CCD in the OD was accompanied by choroidal vessel dilation and choroidal vascular hyperpermeability. Two years and 7 months post-surgery, intraocular pressure spiked to 50-54 mmHg but settled at 12 mmHg 1 week later. CCD resolved, and choroidal folds and SRD disappeared, with decreased choroid thickness. Two years and 10 months postoperatively, there was no SRD recurrence at 10 mmHg on two antiglaucoma eye drops, and best-corrected visual acuity remained stable at (1.0)/(1.0). This case suggests that SRD may result from increased choroidal vessel permeability and retinal pigment epithelium dysfunction secondary to prolonged CCD/low IOP after MIGS. The prolonged disease course may be attributed to the balance between aqueous humor excretion and absorption, influenced by the limited size of the cyclodialysis cleft caused by MIGS.