Background/Aims: To investigate the dynamics of macular hole (MH) closure in gas-filled eyes starting 20 min after vitrectomy using swept source optical coherence tomography (SS-OCT). Methods: Twenty consecutive eyes with MH underwent vitrectomy with internal limiting membrane peeling and gas tamponade. SS-OCT imaging was performed approximately 20 min after the operation, and then once a day, until MH closure was confirmed. The correlation between the base, top and minimum hole diameters and the duration required for MH closure was investigated. Results: MH closure in gas-filled eyes was confirmed in 1 eye on day 0, 10 eyes on day 1, 2 eyes on day 2, and 3 eyes on day 3, at which times face-down posturing was discontinued without MH recurrence. SS-OCT revealed a distinct closure pattern within the first 24 h postoperatively. MHs closing by day 1 had a significantly smaller minimum diameter (312.5 ± 105.2 µm) than holes closing on day 2 or later (510.8 ± 153.5 µm; p = 0.019). Conclusions: SS-OCT enables tomographic images of MH in gas-filled eyes immediately postoperatively, thus permitting early discontinuation of, or no necessity for, face-down positioning upon confirmation of MH closure.