TB infection in patients after kidney transplantation remains a concern in a successful long-term outcome. This retrospective, descriptive study was performed on tuberculosis infection after kidney transplantation in the Department of Infectious Disease of the First Affiliated Hospital of Zhejiang University, a tertiary care hospital in China, from January 2011 to April 2017, with the aim to explain the clinical features of active tuberculosis after kidney transplantation and explore the correlated factors for diagnostic delay and mortality. It included 48 cases. All these cases were followed up for at least 12 months after anti-tuberculosis therapy, except the ones who died during this period. The median time of transplantation to active tuberculosis of these 48 patients was about 5.4 years. The time from a first hospital visit to the diagnosis (diagnostic delay) of 12 (25%) cases was more than 30 days. The correlated factors for the diagnostic delay more than 30 days were a fever for more than 2 weeks and antibiotic use for more than 2 weeks. Nine (18.8%) cases died during the anti-tuberculosis therapy or following-up period due to TB relapse. The risk factors for mortality were severe complications, such as encephaledema, severe pneumonia, intestinal perforation, liver function failure, and the following multiple-organ failure. In conclusion, the possibility of tuberculosis infection should be carefully assessed and sometimes diagnostic anti-tuberculosis therapy may be required for patients who had a fever for more than 2 weeks or used antibiotics for more than 2 weeks after kidney transplantation. Severe complications and the following multiple-organ failure might increase the mortality among these patients.