The purpose of the present study was to compare the use of lorazepam plus nitroglycerine (NTG) versus NTG alone in the reduction of cocaine induced chest pain in the emergency department. The secondary objective of the study was to help determine the safety of lorazepam in the treatment of cocaine- associated chest pain. The study was a prospective, randomized, single-blinded, controlled trial conducted at an university-affiliated urban emergency department (ED). All patients who presented with cocaine-associated chest pain were enrolled. Exclusion criteria included age greater than 45 years, documented coronary artery disease, chest pain of more than 72 hours duration, or pretreatment with nitroglycerin. Patients were given either sublingual nitroglycerine (SL NTG) (Group 1) or SL NTG plus 1 mg of lorazepam intravenously (Group 2) every 5 minutes for a total of 2 doses. Chest pain was recorded on an ordinal scale of 0 to 10 at baseline, and then at 5 minutes after each dose. Adverse reactions to medication were also recorded. Twenty-seven patients met the inclusion criteria and were enrolled in the study. The average age of these subjects was 34.1 years, and 67% were men. The NTG-only group consisted of 15 patients and the NTG-plus-lorazepam group consisted of 12 patients. Baseline mean chest-pain scores were 6.87 in Group 1 and 6.54 in Group 2, with no differences between groups. Five minutes after initial treatment, mean scores for the two groups were 5.2 and 3.9, respectively, with a difference in means of 1.24 (95% confidence interval [CI] −0.8-3.8). Five minutes after the second treatment, the mean scores were 4.6 and 1.5, respectively, with a difference in means of 3.1 (95% CI 1.2-5). Kruskal-Wallis testing showed a significant difference in pain relief between the two study groups (P = .003), with greater pain relief noted at 5 and 10 minutes in the NTG-plus-lorazepam group (P = .02 and P = .005, respectively). All patients in the study were admitted to the hospital, but no patient in either group had an acute myocardial infarction or cardiac complications in the ED. No adverse side effects were noted for either group. The early use of lorazepam with NTG was more efficacious than NTG alone, and appears to be safe in relieving cocaine-associated chest pain. (Am J Emerg Med 2003;21:39-42.