Objectives Malnutrition can be a significant problem among older adults and the medically compromised individuals, contributing to morbidity and mortality. Causes of malnutrition are complex and varied. Oral nutritional supplements (ONS) are often prescribed to individuals with or at risk of malnutrition. Although beneficial, concerns have been raised about their cariogenic potential. The purpose of this study is to report on the currently available ONS in Australia, focusing on factors that impact their cariogenicity. Methods A list of ONS was compiled based on their availability in Australia and indication for use in adults with or at risk of malnutrition. Data concerning composition, clinical indications and the recommended daily consumption was ascertained from product labels, company websites and customer services. Measurements of pH and viscosity were obtained for all ONS. Results A total of 33 ONS were identified, which were noted to vary in their cariogenic potential. Conclusions Recognition of the possible caries risk associated with the use of ONS is important. Awareness facilitates the making of informed decisions when ONS are chosen. When the need arises to use ONS in individuals where the associated caries risk is considered significant, caries preventive protocols should be implemented by the prescriber.