BACKGROUND: Despite all efforts, the incidence of severe coronavirus disease 2019 (COVID-19) infection has been high in renal transplant recipients, as in other groups (eg, older adults, patients with comorbidities or immunosuppression). The detection of any possible predictor of gravity could improve the early approach in these patients. PATIENTS AND METHODS: We registered data from renal transplant recipients with severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection in our area for a year (March 2020 to March 2021). We collected demographics, comorbidity, body mass index, lymphocyte count, and vitamin D levels before the diagnosis. We performed statistical analysis using SPSS Statistics version 20 (IBM Corp, Armonk, NY, United States). RESULTS: Of 63 patients, 57.1% required hospital admission and 14.3% required intensive care. The incidence of acute renal failure was 28.6%; 34.9% developed hyperinflammatory syndrome; 67% had lymphopenia, which was severe in 13.1%; and 11 patients died. There was significant correlation between lymphocyte count before and during the infection. For hospitalization, we found differences in age, pulmonary disease, and renal function. Related factors for admission to an intensive care unit were obesity, severe lymphopenia, altered renal function, and low level of vitamin D. Predictors for mortality were age, renal function, and minimum lymphocyte count. CONCLUSION: In kidney transplant recipients with COVID-19 infection, renal function determines hospitalization, and body mass index determines admission to an intensive care unit. Previous vitamin D levels are also significantly lower in patients requiring intensive care. The analysis of lymphocyte count previous to infection is correlated with the minimum level during the disease, which is a predictor of mortality, and could be a prognosis factor.