Background Our aim was to examine the prevalence and characteristics of difcult-to-treat HIV in the current Swedish HIV cohort and to compare treatment outcomes between people with difcult and non-difcult-to-treat HIV. Methods In this cross-sectional analysis of the Swedish HIV cohort, we identifed all people with HIV currently in active care in 2023 from the national register InfCareHIV. We defned fve categories of difcult-to-treat HIV: 1) advanced resistance, 2) four-drug regimen, 3) salvage therapy, 4) virologic failure within the past 12 months, and 5) ≥ 2 regimen switches following virologic failure since 2008. People classifed as having difcult-to-treat HIV were compared with non-difcult for background characteristics as well as treatment outcomes (viral suppression and selfreported physical and psychological health). Results Nine percent of the Swedish HIV cohort in 2023 (n = 8531) met at least one criterion for difcult-to-treat HIV. Most of them had ≥ 2 regimen switches (6%), and the other categories of difcult-to-treat HIV were rare (1–2% of the entire cohort). Compared with non-difcult, people with difcult-to-treat HIV were older, had an earlier frst year of positive HIV test and lower CD4 counts, and were more often female. The viral suppression rate among people with difcult-to-treat HIV was 84% compared with 95% for non-difcult (p = 0.001). People with difcult-to-treat HIV reported worse physical (but not psychological) health, and this remained statistically signifcant after adjustment for age, sex, and transmission group. Conclusions Although 9% of the HIV cohort in Sweden in 2023 were classifed as having difcult-to-treat HIV, a large proportion of these were virally suppressed, and challenges such as advanced resistance and need for salvage therapy are rare in the current Swedish cohort. [ABSTRACT FROM AUTHOR]