Abstract Aims To evaluate the clinical and genetic virulence characteristics of critically ill patients with hypervirulent Klebsiella pneumoniae (hvKP) and classic KP (cKP) infection. Methods and Results The patients included in this retrospective study (n = 225) were grouped according to their hvKP (n = 114) or cKP (n = 111) status, and their clinical characteristics were analysed and compared. Cox multivariate analysis was conducted to determine the risk factors for hvKP infection. Length of hospital stay, length of intensive care unit stay, duration of mechanical ventilation and 28-day survival rate were similar between the groups. However, the incidence of septic shock was higher in the hvKP group (16.7%) than in the cKP group (8.1%). Conclusions There was a high rate of hvKP infection in this population. Compared to patients with cKP infection, those with hvKP infection showed a higher probability of having septic shock; nevertheless, survival and length of hospital stay were similar between the groups. Risk factors for hvKP infection included hospital-acquired infection and renal insufficiency. Significance and Impact of the Study This study presents relevant information on the characteristics of hvKP infection in a Chinese population, and this promotes early diagnosis and supports the view that the prevalence of hvKP is high in China.