The 1992 Canadian Association of Gastroenterology consensus conference on gastroesophageal reflux disease (GERD) recommended a therapeutic trial of H2 receptor antagonists as a cost effective approach to the management of patients with typical symptoms of GERD. Omeprazole, with its increased potency and efficacy of acid suppression, appears to be the ideal diagnostic test therapy for GERD. However, there is little evidence in the literature to support this approach. Omeprazole has the potential to mask other disorders such as peptic ulcer disease, thereby delaying appropriate testing for and eradication of Helicobacter pylori. Therefore, omeprazole therapeutic trials should be used with caution in the diagnosis of GERD. The conventional step up therapy is the least costly and reasonably effective approach to treat the majority of patients with mild to moderate symptoms of GERD. For patients who fail therapy or have complications of GERD, the recently proposed step down therapy is probably more effective and appropriate. As physicians become more comfortable with the long term use of proton pump inhibitors, step down therapy may well replace the more conservative step up approach to therapy.