Postoperative hypotony is not rare. When it occurs, effective treatment must be initiated to avoid secondary complications. We report two cases of postoperative hypotony that have been treated successfully with a single injection of balanced salt solution (BSS) into the anterior chamber. One patient developed hypotony three months after combined cataract surgery and trabeculectomy with the use of Mitomycin C (MMC). The cause of hypotony remained unknown. Leakage, hyperfiltration, cyclodialysis, and other possible causes had been excluded. With a single injection of BSS into the anterior chamber the long-standing hypotony was successfully managed. A second patient with hypotony after pars plana vitrectomy was also treated successfully with an injection of BSS into the anterior chamber. We conclude that an injection of BSS into the anterior chamber is an inexpensive and efficacious remedy for postoperative hypotony of unknown etiology.