['Proton pump inhibitors are the most potent drug treatment for gastro-oesophageal reflux disease. Pre-meal dosing maximizes efficacy while sub-optimal dose timing may limit efficacy.', 'To determine the prevalence of sub-optimal proton pump inhibitor dosing in a community-based gastro-oesophageal reflux disease population.', 'One hundred patients on proton pump inhibitors referred for persistent gastro-oesophageal reflux disease symptoms were questioned about their proton pump inhibitor dosing habits and classified as optimal or sub-optimal dosers. Optimal dosers took proton pump inhibitors with or up to 60 min before meals. Sub-optimal dosers took proton pump inhibitors >60 min before meals, after meals, as needed, or at bedtime.', 'Forty-six percent dosed optimally. Fifty-four percent dosed sub-optimally with 21 of 54 (39%) dosing >60 min before meals, 16 (30%) after meals, 15 (28%) at bedtime and two (4%) as needed. Only 6% of the subjects on once-daily proton pump inhibitor regimens and 33% of subjects taking proton pump inhibitors two- to three times daily dosed in a manner that maximized acid suppression (15-30 min before a meal).'] Is sub-optimal proton pump inhibitor dosing prevalent in patients with poorly controlled gastro-oesophageal reflux disease?