OBJECTIVES:   Generic prescribing is important in South Africa.  Many medical aid schemes will only reimburse the cost of the generic product, and a co-payment is required if a patient wants to use the originator product.  The primary aim of this study was to investigate originator versus generic prescribing focussing on proton pump inhibitors (PPIs). METHODS:  Prescription data were obtained from a private medical aid administrator in South Africa.  The data covered 2010 and included medication, procedures and devices (a total of 2126264 records).  For the purpose of this study, only PPI medicine items were extracted and analysed (MIMS category 12.4.4).  Basic descriptive statistics were calculated. RESULTS: A total of 20537 PPIs were prescribed (only 18.56% on the chronic option of the medical aid schemes).  Five different PPI active ingredients were prescribed to 7060 patients (50.88% female patients).  Omeprazole was the most often prescribed PPI, accounting for half of all PPI prescribing (50.78%), followed by esomeprazole (19.83%) and lansoprazole (18.04%).  Eight different trade names of omeprazole were prescribed (one generic product accounted for 56.00% of all omeprazole prescriptions and 56.08% of the cost of omeprazole prescriptions).  The originator product only accounted for 1.75% of omeprazole prescribing frequency and 3.07% of prescribing cost.  Only one trade name of esomeprazole was prescribed (no generic equivalents) and nine trade names of lansoprazole (the originator accounted for 1.43% of prescribing frequency and 2.51% of cost).  On average, esomeprazole had the highest average cost of R308.97, followed by rabeprazole (R236.58).  Both these products do not have generic equivalents on the South African market. CONCLUSIONS:   Further studies that include dosage forms and prescribed daily doses (PDDs) should be conducted alongside cost analyses.  A clear difference between the prescribing and cost of originator versus generic prescribing was detected in this study.