Background: At present, temporary pacemaker implantation is very common in the treatment of cardiovascular diseases in adults. However, the number of pediatric pacemakers implanted is still relatively small, and relevant research is also far less than that of adults. This study aimed to explore the application of temporary pacemakers in children with acute and critical cardiovascular diseases. Methods: The clinical data of children with cardiovascular diseases who were treated with temporary pacemakers in Tianjin Children's Hospital from October 2017 to February 2021 were analyzed retrospectively. Results: A total of 13 children with cardiovascular diseases were included in this study, including 4 males and 9 females, mean age of 71.2±56.3 months, and median body weight of 15.5 kg. There were 9 children with endocardial pacing and 4 children with epicardial pacing. The types of diseases included fulminant myocarditis (n=8), complete atrioventricular block (CAVB; n=1), and arrhythmias after open heart surgery (n=4). The median time from onset to admission was 1.0 days in children with endocardial pacing and there was cardiac arrest in 2 children, heart failure in 9 children, cardiogenic shock in 8 children, and Adams-Stokes attack in 7 children. The median time from admission to implantation of temporary pacemakers was 3.0 h and the operation time was 55.0±19.4 min. All 4 children with epicardial pacing had pacemakers implanted during operation because of CAVB. The pacing mode was VVI mode. The initial perceptualvoltage was 1-2 mv, the output voltage was 5v, and the pacing frequency was 70-145 bpm. A total of 11 children reverted to sinus rhythm within 5.0 (1.8-34.0) h and the working time of temporary pacemakers was 134.0 (15.0-191.0) h. There was poor pacing in 2 children and catheter displacement in 1 child during pacing. A total of 12 children were followed up for 20.0±12.5 months and 1 was lost to follow-up. During the follow-up period, the cardiac functions were basically normal and no new arrhythmia appeared.Conclusions: Temporary pacemakers have the advantage of simple operation, definite effect, and safety which has a remarkable effect in the treatment of acute and critical cardiovascular diseases in children.