Background: Uninterrupted oxygen supply is an essential hospital facility. Careful planning is needed to prevent major mishaps in case of failure. We undertook a survey to assess vulnerability of oxygen supply systems to disasters. Methodology: Hospitals in South India were stratified and randomized based on their bed strength. A structured telephonic interview was done to the managers of engineering departments in these hospitals. The questionnaire included type of oxygen source, location, changeover mechanism, and alarm systems. Results: Of the 30 hospitals randomized, adequate information was obtained from 25 hospitals. The primary source of the supply was cylinder manifolds in 48%, liquid oxygen in 40%, and concentrators in 12% hospitals. A reserve source of oxygen supply was available in 64% hospitals; 44% with cylinders, and 20% with liquid oxygen. Only 52% of the hospitals had a reserve supply in a different location from the primary. Changing the source of supply was manual in 44% of hospitals and 20% had an automatic change over system installed. There were effective zonal and central alarms in only 12% of hospitals. Conclusion: Most of the hospitals rely on a single pipeline from a single location inviting mishaps during the disasters. Contingency planning to reduce the risk of an uninterrupted supply should involve automatic changeover systems to a backup source with physically separated feed lines. Primary, secondary, and reserve supply could involve the use of liquid oxygen, oxygen concentrators, or cylinder manifold systems in various combinations depending on the size of hospital, proximity to a liquid oxygen plant and risk.