The purpose of the present study paper was to review the reported prevalence of the oral manifestations of HIV (OM-HIV) worldwide since 1980, and to determine the global variation in its prevalence over time. PubMed, Scopus, Embase and Google Scholar were searched. The filter "English" was used. The timeframe searched was 1980- 2015. The PRISMA flow chart was used. Data were extracted using the Joanna Briggs Institute standardized data extraction form and transferred to SPSS version 22 for analysis. The systematic review of 97 studies (70 low bias risk) showed that the prevalence of OM-HIV continue to be significant in developing countries. Globally and through all the decades, oral candidiasis remained the most commonly encountered OM-HIV, including among patients on antiretroviral therapy (ART) (26.2%). Hairy leukoplakia was more prevalent in Europe and America compared with Africa and Asia. Oral warts were reported more often in studies on patients receiving ART. Interestingly, salivary gland disease decreased in the developed world and increased in developing countries over time. Despite the changing pattern of these conditions over time, there is no evidence that the OM-HIV have become of less significance globally. Maintaining the drive for high-quality research in the subject will have an impact on less developed countries to help address oral health inequalities.