Antiretroviral therapy (ART) is a lifelong combination therapy which has been very promising in managing HIV/AIDs but reported to have several adverse events on the recipients, affecting the desired antiretroviral therapeutic goals. Adverse drug event detection and prevention therefore become very important safety culture maintenance tools among patients living with HIV/AIDS. The designed protocol provided step by step approaches to develop and validate a trigger tool for detection of adverse drug events (ADE) among adult HIV/AIDS patients. The approaches involved include a baseline (Pre-trigger tool development) retrospective clinical record review to establish a baseline ADE detection capacity of a conventional non-trigger tool method; the Delphi panel process to develop the trigger tool in question; Face and content validity approach for validation of the developed trigger tool; Pilot test of the trigger tool using small clinical record sample; determining the effectiveness of the developed trigger tool through the retrospective clinical record review of same samples reviewed at the baseline. Finally, the protocol described the process of determining the feasibility of the developed trigger tool through the survey of the clinical record review team members.