Objectives: Retrospective study of the causes, location, configuration, treatment and outcome of long bone fractures in newborn calves. Material and methods: The medical records of 125 calves presented during a 16-year period because of fracture of the humerus (3 calves), radius/ulna (14), femur (50) or tibia (58) were evaluated. The majority of calves (61.6%) sustained the fractures during assisted delivery. Of 125 calves, 107 were treated and 18 were euthanized because of concurrent diseases. Conservative treatment was used in 16 calves and surgical treatment in 91. Four of the latter were euthanized because of muscle contraction which prevented fracture reduction, and five others died in surgery. Results: Fracture healing occurred after conservative treatment in 10 of 16 calves and after surgical treatment in 44 of 82 calves. The outcome was better in calves with plate and clamp-rod internal fixation (37/58 healed) than with intramedullary pinning (4/16 healed) or external fixation (3/8 healed). There were significant associations (chi2-test, p<0.01) between concurrent diseases and choice of therapy and fracture healing. Of 67 calves that developed complications, only 26 could be cured. Common complications were implant loosening and instability, which were often followed by osteomyelitis and sepsis. Implants were removed in 39 of 44 surgically treated calves that survived up to 6 months postoperatively. Long-term follow up (> 6 months postoperatively) by clinical and radiographic re-examination (25 calves) or telephone inquiry (29 calves) revealed that 54 animals were sound and had returned to their intended use. Conclusions and clinical relevance: The treatment of long bone fractures in newborn calves remains difficult because of a high incidence of complications. These are most likely attributable to trauma during delivery, which results in insufficient colostrum intake and predisposes to concurrent diseases. In addition, the characteristics of juvenile bones do not provide sufficient physical strength for implants. Therefore, professional and diligent assistance during forced extraction, particularly in presentations with “stifle lock” or “hip lock”, is required to minimize the incidence of long bone fractures in newborn calves. Most cases require surgical fixation, which is time consuming, expensive and carries a guarded prognosis.