Background: Real-life data on single-tablet regimen (STR) dolutegravir/abacavir/lamivudine (DTG/ABC/3TC) is scarce, and concerns about DTG neuropsychiatric adverse events (NP-AEs) have recently arisen. Objective: To explore the effectiveness and safety, in particular NP-AEs, of DTG/ABC/3TC in a cohort of HIV-1 adult infected patients. Pill burden, adherence to this STR, and the impact of switching on costs were also evaluated. Methods: This was an observational, retrospective study. The study population included antiretroviral therapy (ART)-naive and treatment-experienced (TE) patients who started DTG/ABC/3TC between February 1, 2016, and October 31, 2016. Effectiveness and safety were analyzed at week 48 (W48) by intention-to-treat analysis. The Cox regression model was used to investigate predictors of DTG/ABC/3TC discontinuation. Results: A total of 253 patients were included (44 ART naïve, 209 TE). At W48, the proportion of patients with virological suppression was 72.7% (95% CI = 58.4-87.0) in ART-naive patients, 85.6% (95% CI = 80.3-90.9) in previously suppressed TE patients, and 86.4% (95% CI = 65.1-97.1) in previously not suppressed TE patients. The rate of protocol-defined virological failure was 4.3%. The incidence of AEs was higher in the subgroup of ART-naive patients (56.1% vs 39.0%), with a rate of interruptions for this reason of 13.6% and 7.6%, respectively. The incidence of NP-AEs was 20.6%, with 3.9% of patients requiring discontinuation. Patients who had switched from a raltegravir-containing regimen discontinued DTG/ABC/3TC because of AEs more frequently (relative risk = 2.83; 95% CI = 1.04-7.72; P = 0.041) in the multivariate analysis. After switching to DTG/ABC/3TC, the median pill burden was reduced from 3 to 1 and the proportion of patients with an adherence <90%, from 20.1% to 12.0%. The annual per-patient ART costs increased by €48 (0.6% increase). Conclusion and Relevance: DTG/ABC/3TC is an effective strategy as first-line and switching ART. Our data suggest a worse tolerance in ART-naive patients, although the rate of discontinuation resulting from NP-AEs was relatively low. In the short-term, the adherence was slightly improved without significant changes in costs.