Objective To investigate the characteristics of adverse drug event (ADE) related to tacrolimus (Tac) in pediatric solid organ transplant recipients. Methods The data were retrieved from the US Food and Drug Administration Adverse Event Reporting System database from the first quarter of 2004 to the second quarter of 2023. The ADE data of pediatric organ transplant recipients with Tac as the primary suspected drug were extracted. The relationship between Tac and ADE was quantitatively analyzed by proportional imbalance method. Basic characteristics and signal strength of ADE related to Tac were analyzed. ADE related to Tac in children of different ages and different types of organ transplantation were analyzed. Results A total of 1 443 children's ADE reports involving Tac were screened, including 188 cases (13.0%) of heart transplantation, 668 cases (46.3%) of liver transplantation, 531 cases (36.8%) of kidney transplantation and 56 cases (3.9%) of lung transplantation. The median age of children was 10 years old. The top three countries with ADE reporting were the United States, France and the United Kingdom. China reported 26 cases, accounting for 1.8%. Infection and infectious diseases accounted for the highest proportion (20.96%) in ADE related to Tac, including EB virus and cytomegalovirus infection, etc. Infection and infectious diseases occupied the largest proportion of ADE related to Tac in children of different ages, whereas the pathogen types were different. Rejection, unstable immunosuppression level and renal function damage were also common ADE related to Tac in children of all ages. Nervous system disease was the main ADE in heart transplant recipients, while infection and infectious diseases were more common in liver and kidney transplant recipients. Rejection was the most common ADE in lung transplant recipients. Conclusions ADE related to Tac possess different distribution characteristics in different types of organ transplantation. Extensive attention should be paid to individualized drug monitoring and risk assessment in pediatric organ transplant recipients, thereby optimizing Tac treatment and reducing the risk of ADE.