Purpose Whilst recurrence and amputation rates in post-traumatic osteomyelitis (PTOM) are described, limb specific functional outcomes are not, leading to a knowledge gap when counselling patients prior to management. We aim to investigate the patient reported outcomes (PROMS) of this patient group to provide reference for discussions with patients prior to embarking on treatment. Methods Single institution cross-sectional retrospective study of all patients presenting with PTOM of the tibia/femur over a 7-year period. Alongside recurrence and amputation rates, patient reported outcomes were recorded including the lower extremity functional scale (LEFS), EQ-5D-3L and EQ-VAS. Results Seventy-two patients (59 male; median age 46 years) were identified. Treatment was principle-based and included debridement (with Reamer-Irrigator-Aspirator (RIA) in 31/72), local antibiotics (52/72), soft tissue reconstruction (21/72) and systemic antibiotic therapy in all cases. PROMS were collected in 84% of all eligible patients at a median of 112-month post-treatment. Twelve patients experienced recurrence, whilst nine underwent amputation. The median LEFS was 60, the EQ-5D-3L index score was 0.760, and the EQ-VAS was 80. These scores are substantially lower than those seen in the general population (77, 0.856 and 82.2, respectively). LEFS was significantly higher, where RIA was utilised (69.6 vs 52.8; p = 0.02), and in those classified as BACH uncomplicated (74.4 vs 58.4; p = 0.02). EQ-5D-3L was also higher when RIA was utilised (0.883 vs 0.604; p = 0.04), with no difference in EQ-VAS scores. Conclusions Patients with PTOM report functional outcomes below that of the general population, even when in remission. Improved outcomes were associated with uncomplicated disease and the use of RIA.