Literacy levels are increasingly important in health care because professional nurses and other health care professionals often use written health education materials as a major component in patient education. In South Africa, no current instrument is available to assess the literacy levels of patients in the primary health care setting, though several instruments have been developed and validated internationally. The purpose of this paper was to adapt and validate the Rapid Estimate of Adult Literacy in Medicine Revised (REALM-R) to the South African context. The REALM-R is a short instrument that is designed to rapidly screen clients in the primary health care setting for low health literacy. A modified Delphi-technique was used to measure the judgement of a group of experts for the purpose of making a decision. Eight experts in the field of Nursing Science were selected purposively to obtain the most reliable consensus. Data was collected by means of a selfreport whereby participants responded to a series of questions posed by the researcher. Descriptive statistics was used for analysing data. The REALM-R was adapted to the South African context to ensure that the literacy level of South African clients is measured with an appropriate instrument.