Hospital pharmacies in Massachusetts were surveyed to determine their patterns of stocking antidotes. Mailed questionnaires were completed by hospital pharmacy directors at 82 of 93 acute care institutions (87% response rate). Results confirmed great variability in on-site accessibility of antidotes. Only 8 of the 82 hospitals (9.8%) stocked all of 14 common antidotes inventoried by the survey. Even fewer hospital pharmacies stocked specific antidotes (eg, Crotalid anti-venin, digoxin-specific Fab antibodies, pyridoxine) in an adequate quantity to treat one poisoned adult. Larger hospitals and those with a 24-hour pharmacy were more likely to have certain antidotes than smaller institutions. We conclude that Massachusetts hospitals do not carry complete inventories of 14 common antidotes. It is important that poisoned patients be referred to medical centers with adequate toxicological care. Improved guidelines for the accessibility of antidotes need to be developed and made available to hospital pharmacies and emergency departments.