Hard-to-heal arterial leg ulcers in older adults are a challenging and complex condition. In this quasi-experimental study, three treatment approaches were compared. The purpose was to investigate (1) the healing time of arterial leg ulcers in older adults (≥ 70 years) who underwent photobiomodulation, revascularisation, or conservative treatment; (2) the importance of factors associated with impaired healing; and (3) ulcer recurrence after healing with photobiomodulation. Participants who received photobiomodulation (n = 51) were frail older adults recruited from municipal home healthcare and matched with participants who received revascularisation (n = 71) or conservative treatment (n = 153). The latter two groups were retrieved from the Swedish Quality Registry RiksSår for ulcer treatment. Photobiomodulation was performed at wavelengths of 635 and 904 nm twice weekly. The results showed that the photobiomodulation group had a significantly shorter healing time (p < 0.001) and a higher proportion of healed ulcers; photobiomodulation 66.7%, revascularized 50.7% and conservatively treated group 41.2%. The median healing times for the photobiomodulation group were 135 days (confidence interval 95–175), compared to 252 (confidence interval 181–323) and 316 (confidence interval 192–440) in revascularized and conservatively treated groups, respectively. Neither ulcer duration nor other pretreatment factors exerted clinically relevant effects on healing time. In this study, recurrence within 24 months of healing with photobiomodulation was < 12%. In conclusion, photobiomodulation has the potential to heal hard-to-heal arterial ulcers markedly faster than revascularisation or conservative treatment. It could be a suitable treatment alternative for frail older adults, including those with previous substantial ulcer duration.