Background: Proper drug prescribing can contribute immensely to reducing overall morbidity, mortality, and cost of pharmacotherapy, particularly in the management of heart disease. Currently, no studies have been implemented on the appropriateness of cardiologist prescribing among hospitalized pediatric patients in Palestine. This study aimed to compare the prescribing pattern of pediatric cardiologists during clinical pharmacist intervention versus routine cardiologists' practice at a tertiary care hospital in Palestine. Methods: A comparative study of 48 pediatric patients who were admitted to the cardiology ward in 2020 and readmitted in 2021 was conducted. This comprised two stages: routine practice stage (S0) of cardiologists without clinical pharmacist intervention, and intervention stage (S1) where clinical pharmacist prospectively involved in cardiology teamwork. Prescribing indicators and length of hospital stay were compared between the two study stages using Pearson's chi- square and paired t-test. Results: Compared with the routine practice stage, drugs prescribed per patient were significantly lower in the intervention stage ( mean 5.98 S1 versus 6.87 S0; P=0.043). Higher drugs prescribed by generic names were found in the intervention stage (97.2% S1 versus 72.1% S0; P= 0.002). Patients in the intervention stage encountered significantly fewer antibiotics than in the routine practice stage (60.4% and 77.1%, respectively; P=0.009). The mean length of hospital stay was significantly reduced from 8.22 days in the routine practice stage to 6.93 days in the intervention stage (P=0.032). There were no significant differences in the prescribing of essential drugs (99.3% S1 versus 95.2% S0; P=0.152) and injections (75.0% S1 versus 73.0% S0; P=0.496) between the two stages. Conclusion: Clinical pharmacist intervention has optimized the prescribing pattern of pediatric cardiologists and reduced the length of stay for hospitalized pediatric patients. Palestinian health leaders have to support the involvement of clinical pharmacists in cardiology and other disciplines to promote rational prescribing and drug utilization.