Our goal was to investigate 31 adult patients (mean age 29 years, range 18-62 years) meeting Rome II criteria for cyclic vomiting syndrome (CVS). All subjects completed a clinical questionnaire, a Hamilton Rating Scale for Anxiety (HAM-A) and Zung Depression Inventory. Gastric emptying time was assessed in 30 subjects and electrogastrogram (EGG) in 11 between acute attacks. Twenty-seven patients treated with amitriptyline completed a follow-up questionnaire. The mean age of onset of the patients was 30 years (range 14-53 years) and cycles of nausea and vomiting were accompanied by often-severe epigastric and diffuse abdominal pain. A typical attack ranged from 1 to 14 days, with the majority being 4-6 days. The HAM-A revealed that 84% had an anxiety disorder, and based on Zung Depression Inventory 78% suffered from mild-to-severe depression. Only 4 (13%) patients reported migraine, but 14 had a family history of migraine. Gastric emptying time was rapid in 23 (77%), normal in 4 and delayed in 3. The EGG was abnormal in 7 of 11 patients, with 4 having tachygastria. Of 13 patients using marijuana, 7 had symptom relief, while 2 had resolution of CVS after stopping use. The overall treatment experience in the 24 patients receiving amitriptyline up to 1 mg kg(-1) day(-1) for at least 3 months indicated that 93% had decreased symptoms and 26% achieved full remission. Cyclic vomiting syndrome in adults has the following hallmarks: prominence of accompanying abdominal pain and increased prevalence of anxiety and depression, rapid gastric emptying and tachygastric EGG, and successful suppression of attacks by chronic amitriptyline therapy.