To determine if factors associated with medication errors explained perceived harmful outcome from such errors, perceptions of vividly recollected medication errors were reported by a convenience sample of 206 hospital-employed RNs and LPNs who completed the Medication Error Risk Profile (MERP). Symptoms related to the error, radiology studies performed, the toxicity of the medication given, adverse drug reaction unrecognized at first, and transfer of the patient to another unit explained 38% of the variance in perceived harmful outcome. The implications of the this study for medical-surgical nurses are explored.