AIM: To observe the efficacy of simplified one-step thermokeratoplasty for the treatment of severe acute corneal hydrops in keratoconus. METHODS: In this retrospective, noncomparative clinical study, 10 patients (10 eyes) with acute hydrops in keratoconus were treated with simplified one-step thermokeratoplasty. Pain, changes in the corneal curvature, thickness, and size and morphology of the Descemet membrane breaks were detected before and after surgery. Eight patients were successfully treated using modified deep anterior lamellar keratoplasty (DALK). Graft transparency, visual acuity, and immunological rejection were evaluated for 6 to 12mo. RESULTS: Pain and corneal oedema were promptly alleviated, and the intrastromal ruptures diminished within 3 to 6wk after thermokeratoplasty. At 3 to 6wk after corneal oedema was faded, Descemet membrane breaks and intrastromal ruptures were healed. Two patients did not undergo subsequent corneal transplantation after thermokeratoplasty. Eight patients underwent DALK successfully and safely after thermokeratoplasty, without corneal perforation. Central corneal opacity faded or disappeared within 6mo. The mean best-corrected visual acuity was increased to 20/30 at 12 mo after DALK. No one was observed with any immune rejection. CONCLUSION: One-step thermokeratoplasty can successfully and efficiently accelerate the absorption of prominent corneal oedema in severe acute hydrops patients. This simple procedure with no complications can be performed in the emergency department by residents. This method can improve the safety of DALK and obtain good postoperative vision. Long-term management of acute corneal hydrops using simplified one-step thermokeratoplasty seems promising.