INTRODUCTION: Switching to a rilpivirine, tenofovir and emtricitabine (RTE) single-tablet regimen (STR) has been evaluated in a limited number of virologically suppressed patients. The aim of this study was to describe clinical outcomes in HIV-positive patients switched from a suppressive antiretroviral regimen to RTE STR in routine clinical practice. METHODS: In this retrospective study of antiretroviral-treated patients with <50 copies of HIV RNA/mL switched to RTE STR, virological failure (VF) was defined as two consecutive measurements of ≥50 copies/mL or a single measurement of ≥50 copies/mL followed by any change in treatment. Treatment failure (TF) was defined as VF or discontinuation of the STR for any reason. Univariate mixed-linear models were used to identify differences in laboratory parameters over time. RESULTS AND DISCUSSION: The analysis involved 307 patients (83% males) with a median age of 45.8 years (interquartile range (IQR 39.3-50.9), who were followed up for a median of 7.4 months (IQR 4.6-10.9). VF occurred in three patients (1%) switched from a protease inhibitor (PI)-based regimen, after a median of 2.6 months (IQR 1.6-3.0), and TF in 34 patients (11%) after a median of three months (IQR 1.4-5.8), 24 of whom (71%) were receiving a PI-based regimen at baseline. Overall, there was a slight but statistically significant improvement in the mean monthly change from baseline in CD4+ cell counts (p=0.027), the CD4+/CD8+ ratio (p=0.0001), and Hb (p=0.024), alanine amino transferase (ALT) (p=0.009), total bilirubin (p<0.0001), indirect bilirubin (p<0.0001), total cholesterol (p<0.0001) and triglyceride (p<0.0001) levels. There was also a slight but statistically significant increase in serum creatinine (p=0.0004), aspartate amino transferase (AST) (p=0.001) and liver fibrosis index (FIB-4) (p=0.002), and a decrease in eGFRcreat (p<0.0001) and high-density lipoprotein (HDL) cholesterol (p<0.0001) values. The study limitations include its retrospective design, the relatively short follow-up, and the absence of data concerning the severity of clinical adverse events; however, it does provide new information concerning the laboratory changes that occur in patients switching from PI-based or PI-sparing regimens to RTE STR. CONCLUSIONS: The study findings confirm the efficacy and safety in clinical practice of switching to RTE STR in virologically suppressed patients receiving other antiretrovirals.