This study aims to review pediatric pulmonary hypertension (PH) by comparing the guidelines of the European Society of Cardiology (ESC)/European Respiratory Society (ERS), the American Heart Association (AHA)/American Thoracic Society (ATS), and the European Pediatric Pulmonary Vascular Disease Network (EPPVDN). All three sets of guidelines define PH as having a mean pulmonary artery pressure of ≥25 mmHg and accept the validity of the World Health Organization (WHO) classification system. Every child with a high index of suspicion for PH should undergo an initial work-up of chest X-rays, electrocardiography, and echocardiography. The AHA/ATS guidelines emphasize the necessity of cardiac catheterization and hemodynamic studies. As mentioned in the AHA/ATS guidelines, the symptoms and tests that can detect PH include right ventricle failure, WHO functional class, syncope, echocardiography findings, hemodynamic data, brain natriuretic peptide (BNP)/N-terminal pro-BNP, the 6-min walk test, and cardiopulmonary exercise tests. The EPPVDN guidelines refer to positive acute vasoreactivity test results and growth as risk factors. All three guidelines highlight the importance of treating and following affected children in specialized centers and recommend calcium channel blockers as a first-line treatment in children (aged >12 months) who have a positive acute vasoreactivity test. Children with PH have distinct clinical features. In order to overcome the controversies related to the optimal management of pediatric PH, well-designed clinical studies should be carried out on a large cohort of affected children.