To investigate the clinical characteristics and prognosis of human adenovirus (HAdV) infection in patients with allogeneic hematopoietic stem cell transplantation (allo-HSCT). This is a retrospective case series study. Patients who received allo-HSCT and had symptoms of HAdV infection were tested in the Hematology Department at Perking University People’s Hospital from August 2015 to October 2019. Real-time quantitative PCR was used to detect HAdV DNA from 2 728 patients with potential infection. HAdV DNA-positive patients were defined as having HAdV infection. The clinical features of these patients were analyzed, and a case-pair method was used to select patients without HAdV infection as the control group in a 1∶3 ratio. The clinical results of the two groups were compared using Kaplan-Meier and Log-rank testing. A total of 7 119 samples were tested for HAdV, of which 99 samples from 36 patients were positive. Of these patients, 22 developed HAdV viremia, and 24 patients had concurrent infection with another virus. Nineteen patients had fever (53%), 25 had gastrointestinal symptoms (69%), 11 had respiratory symptoms (31%), nine had reduced liver function (25%), and six had nervous system symptoms (17%). Twenty-three patients developed acute graft-versus-host disease of grade 2 or higher. Of all the patients with HAdV infection, nine were treated with cidofovir, seven of whom became HAdV negative and two had invalid treatment. The median follow-up time was 496 (216, 940) d post-HSCT. The overall survival at 5 years post HSCT was 48.4%±9.2% vs. 91.3%±3.5% (=65.03, <0.001) in patients with and without HADV, respectively. The non-relapse mortality at 5 years post-HSCT was 40.8%±8.8% vs. 4.0%±2.0% (=34.17, 2 degrees. Patients with HAdV infection have poor overall survival and high non-relapse mortality.