HIV drug resistance testing is fundamental in clinical patient management, but data on HIV-1 drug-resistant mutations (DRMs) is scarce in the Caribbean and in Suriname limited to one survey on transmitted resistance. The aim of this study was to address this gap, to gain insight in acquired HIV drug resistance (ADR) prevalence and mutation patterns, and to improve HIV-1 treatment outcome of people living with HIV (PLHIV) in Suriname. A prospective cross-sectional study was conducted from July 2018 through January 2019 among treatment-experienced PLHIV ( = 72), with either treatment failure or antiretroviral therapy restart. Genotypic drug resistance testing was performed and DRM impact on drug effectiveness was examined. Genotypic drug resistance testing revealed 97.2% HIV-1 subtype B, 2.8% B/D recombinants and a ADR prevalence of 63.2% in treatment failure patients, with a predominance of nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations. The most common DRMs were M184V (23.6%) and K103N (18.8%). A high level of non-DRM polymorphisms was observed in both the reverse transcriptase (RT) and protease (PR) gene. Interesting deviations from the existing mutation datasets were noted at position E248 and R83 of the RT gene and L63 and V77 in the PR gene. Full susceptibility to all examined drugs was 54.2%, while high-level drug resistance was estimated at 37.5%, which seems promising for treatment outcomes for PLHIV in Suriname, although cross-resistance to next-generation NNRTIs was already estimated for nearly a quarter of the patients. The meager 2.9% of PR DRMs rendered protease inhibitors as an effective rescue HIV-1 treatment.