OBJECTIVE : There is variability among surgeons on definitions regarding the degree of bone healing of long-bone fractures. A lack of consensus may negatively affect communication between surgeons, and lead to unintended and unwanted variability in treatment of patients suffering from abnormal healing of long-bone fractures. We aimed to identify differences between surgeons regarding their views on the degree of union of long-bone fractures. METHODS : We performed a survey among 114 surgeons who worked at 11 level I trauma centers and 68 level II/III hospitals in the Netherlands. We asked them to represent their institutional colleagues and answer questions regarding their views on the definition, factors influencing bone healing, clinical practice, views on scientific evidence, and the use or need of guidelines for non-union of long-bone fractures. A total of 26 trauma surgeons and 37 orthopedic surgeons responded (59%). RESULTS : Compared to trauma surgeons, more orthopedic surgeons maintain 6 months as the timeframe for classifying a fracture without healing tendencies as a non-union fracture (50 vs 70%; P = 0.019). Compared to orthopedic surgeons, trauma surgeons use the bone scan (46 vs 19%; P = 0.027) and the PET scan (50 vs 5.4%; P < 0.001) more often, and consider medication use to be a factor influencing bone healing more often (92 vs 69%; P = 0.040). Furthermore, they utilize bone marrow aspiration (35 vs 11%; P = 0.029), reaming of long bones (96 vs 70%; P = 0.010), synthetic bone substitutes (31 vs 5.4%; P = 0.012), bone morphogenetic proteins (58 vs 16%; P = 0.001), and the Diamond concept (92 vs 8.1%) more often as treatment modalities for non-union of long-bone fractures. Surgeons agreed on that intramedullary nail osteosynthesis was the treatment option supported by the highest level of evidence. 80% of the respondents feel a need for a clinical guideline on the management of long-bone non-union. CONCLUSIONS : There is no consensus among surgeons on the definition, factors influencing healing, clinical practice, and scientific evidence regarding non-union of long-bone fractures. The vast majority of surgeons believe that their practice would benefit from (inter)national guidelines on this topic, and efforts should be made to reduce surgeon-to-surgeon variability in treatment recommendations and facilitate more homogenous scientific research on non-union of long-bone fractures. METHODS : Level V.