Abstract In this paper cumulative Sum (CUSUM) chart is applied to monitor increase (changes) in the number of HIV/AIDS incidences in Nigeria using the screening result of HIV/AIDS data in Oyo state. The designed scheme is apply to demonstrate the application of the chart and evaluate the performance of the chart in the non manufacturing area. From the evaluation, the chart has a good potential as a SPC tool for monitoring changes in the number of infectious diseases in Nigeria