There currently is no pharmacologic approach to the problem of anticipatory nausea and vomiting (ANV). Lorazepam (Ativan, Wyeth Laboratories, Philadelphia) is an interesting candidate drug if it could block the recall of the unpleasant events associated with chemotherapy, especially if it also has antiemetic properties. Since ANV is a conditioned (learned) response, it may well depend on a memory imprint of the stimulus. This pilot study was designed to use intravenous lorazepam given before and after cisplatin infusion in 32 patients, and to make detailed measurements of nausea, vomiting, recent memory, anxiety, and sedation as well as toxicity. Satisfactory responses occurred in about 70%, as rated separately both by investigator and patient. Forty-six percent did not even recall receiving chemotherapy, regardless of whether or not they vomited; 80% had no significant anxiety after chemotherapy. Adverse reactions included some cases of perceptual disturbance, urinary incontinence, diarrhea, hypotension, and one case of severe transient amnesia. No long-term adverse effects were noted.