OBJECTIVES: The Highly Active Antiretroviral Treatment(HAART) expense plays a crucial role in managing resources properly .Aim of this work is to validate a scoring system that combines appropriateness, drug-spending and clinical outcomes. METHODS: All patients followed by our HIV outpatients service who started a first or an early switch regimen(II line) in 2014 have been enrolled. Demographic and epidemiological data were recorded. Each HIV treatment receives a score resulting from combining its relevance (according to Italian guidelines) and its related monthly cost. The most appropriate and less expensive regimen got a score of 1 point, whilst other are rated declining progressively by 0,05 points according to their value based on the two parameters described above (range: 1-0,1). Furthermore, we followed the clinical course recording CD4 cell increase and HIV viral load decrease as a surrogate marker of quality of life. RESULTS: st line patients and 462 for early switch respectively. 11 Only 9 patients were classified C according to CDC criteria (A=11; B=26). We obtained  an overall appropriateness score of 0,89, tenofovir-Based Single Tablet Regimens (TVD-STR) rated 0,99 , PI-Based Regimens got a score of 0,91. Mean monthly therapy cost was € 627,3 vs. € 719,8 respectively. After three months, all patients were virologically suppressed. CONCLUSIONS: Our study helped in defining the APROSCE system as an efficacious tool to evaluate the correlation of treatment appropriateness, drug expense and clinical outcomes .Higher score is a predictor of better outcomes and less drug expenditure. Related savings might be invested in more complex patients management with multi drug resistant strains or AIDS presenter.