Cardiac complications, such as pulmonary hypertension (PHT), are the leading cause of death in beta-thalassemia patients. L-Carnitine, due to its role in fatty acid oxidation, might help control the elevation in pulmonary artery systolic pressure (PASP). The objectives of this study were to assess the prevalence of PHT in beta-thalassemia major patients, identify clinical predictors for its development, and determine the potential effects of L-carnitine. In total, 32 patients with beta-thalassemia major were recruited; 16 age- and sex-matched children constituted the control group. Cardiac evaluation was performed by using echocardiography. The patients with PHT received 50 mg/kg/day L-carnitine orally for 3 months and were then reevaluated. Based on PASP, the patients were divided into group A without PHT and group B with PHT. The prevalence of PHT was 37.5%. The other echocardiographic measurements were not significantly different between groups A and B. PASP did not have any significant correlation with the following variables: age, total number of blood units received, splenic status, serum ferritin level, and ejection fraction. Following the administration of L-carnitine, there was a significant decrease in the mean PASP from 33.96 +/- 7.85 to 24.11 +/- 7.61. All cardiac dimensions decreased following L-carnitine, but the changes were not statistically significant. Even though beta-thalassemia major resulted in an elevation in the PASP in only a fraction of the patients, it seems to have an impact on the heart dimensions and function of all patients. No clinical predictors were identified. Oral administration of L-carnitine appears to significantly improve PASP.