Proton pump inhibitors (PPIs) are used to treat upper gastrointestinal tract disorders. Their efficacy and perceived safety have led to widespread prescription. This is not without effect, in terms of adverse events and resource utilization. To prospectively assess oral PPI prescription in hospitalized patients. PPI prescription in consecutive hospitalized patients was assessed. Indication and dose were assessed by patient interview and medical record review. Comparisons with current published prescribing guidelines were made. Four hundred and forty-seven patients were included. 57.5% were prescribed PPIs. 26.8% prescriptions were for inappropriate or unclear indications. 68.4% were on higher doses than guidelines recommended, of which 41.6% could have undergone dose reduction, and 26.5% discontinued. In a multivariate analysis, age, gender, and length of stay had no association with PPI prescription. Although aspirin use was appropriately associated with PPI prescription (RR: 1.8, 95% CI 1.127-3.69; p<0.05), the PPI was often given at higher than recommended doses (p<0.001). This may reflect older age and multiple risk factors in this subset. Surgical patients commenced more PPIs and at higher dosages (p<0.001). Omeprazole and lansoprazole were most often inappropriately prescribed (p<0.01, p<0.001, respectively). Inappropriate PPI therapy is still a problem in hospitals, though it appears to be at a lower level compared with previous studies. Awareness of evidence-based guidelines and targeted medicine reconciliation strategies are essential for cost-effective and safe use of these medications.