This research work is a statistical analysis of the HIV/AIDS carrier between the periods 2001 – 2011 in Osun state, Nigeria. The data used was extracted from the Osun State Action Committee on AIDS (SACA) records. Time series analysis was employed to analyze, measure, compute variation and fluctuation in the number of HIV/AIDS carriers in Osun state. Trends were obtained from least square method and the Autoregressive model. The criteria of selection of models used were Akaike information Criteria (AIC) and Schwartz Information Criteria (SIC) of which AIC AR(5) was chosen. The standard error was estimated for both predicted HIV/AIDS carrier rate using least square method and autoregressive model. Based on the fact from the analysis made, it could be concluded that the rate of HIV/AIDS carriers in Osun state fluctuates over the period “t”.