Increasing age is associated with severity and higher mortality of COVID‐19. Telomere shortening is associated with higher risk of infections and may be used to identify those patients who are more likely to die. We evaluated the association between relative telomere length (RTL) and COVID‐19 mortality. RTL was measured in patients hospitalized because of COVID‐19. We used Kaplan–Meier method to analyze survival probabilities, and Cox regression to investigate the association between RTL and mortality (30 and 90 days). Six hundred and eight patients were included in the analysis (mean age =72.5 years, 41.1% women, and 53.8% Caucasic). During the study period, 75 people died from COVID‐19 and 533 survived. Lower RTL was associated with a higher risk of death in women either at 30 (adjusted hazard ratio [HR] (aHR) = 3.33; 95% confidence interval [CI] = 1.05–10.00; p = 0.040) and at 90 days (aHR = 3.57; 95%CI = 1.23–11.11; p = 0.019). Lower RTL was associated with a higher risk of dying of COVID‐19 in women. This finding suggests that RTL has an essential role in the prognosis of this subset of the population.