AIMS: The purpose of the present study is to analyse clinical data of a series of cases who developed nosocomial infection with SARS-CoV-2 in an orthopaedic and traumatology department. PATIENTS AND METHODS: In this non-interventional retrospective study, carried out at a tertiary hospital within the Spanish National Health System, all adult patients who were admitted in the Orthopaedic Surgery and Traumatology Department between March 9th and May 4th, 2020, were included. Clinical, biological and radiological data, as well as mortality rates, were collected from hospital medical records. RESULTS: A total of 293 periods of hospitalization were analysed in 288 patients. Mean age was 66.1 years old and 57.3% were females. Nineteen patients (6.48%) met the inclusion criteria to be categorized as a nosocomial infection with SARS-CoV-2. In a comparison between patients with and without nosocomial infection, age, mortality and hospital length of stay were statistically significant (p < 0.05). The median time from admission to diagnosis of SARS-CoV-2 infection in our cohort was 16 days (6-86 days). No statistically significant differences were found in sex, living situation, reason of admission or period of admission (even if we observed that most of the nosocomial infections (78.9%) occurred in March). CONCLUSION: We have found a 6.48% of nosocomial infection with SARS-CoV-2, but with an important reduction of it after undergoing preventing protocols that included screening RT-PCR test for COVID-19. Age and hospital length stay were statistically significant risk factors for nosocomial infection with SARS-CoV-2. For the progressive restoration of the surgical activity, we recommend to correctly select the patients in elective surgery and to encourage fast-track programs and early discharge of patients with fractures.