A drug-related problem (DRP) may be defined as "an event or circumstance involving drug therapy that actually or potentially interferes with the desired health outcome". Our aim was to determine the frequency and characteristics of DRPs in pediatric patients admitted to a tertiary cardiac care center in the Egyptian capital, Cairo.A prospective observational cohort study involving review of case notes for children aged 0-18 years, admitted to the medical ward and intensive care unit (ICU), was conducted at a tertiary cardiac care center in Egypt. Data collection took place over a three-month period. Daily reviews of patients' records, medication charts and laboratory data were undertaken by the clinical pharmacists to identify DRPs.A total of 60 patients were included in the study (mean age 4.8 years; 53.33% males). Over a three-month period, a total of 313 DRPs were recorded corresponding to an average of 5.22 problems per patient. The most commonly recorded problems related to drug-drug interaction (45.69%), prescribing unnecessary medication (31.95%), under-dosing (21.09%), inappropriate medication (0.96%) and adverse drug reaction (0.32%). Prophylactic antibiotics represented the only unnecessarily prescribed medications. Of the pharmacist suggested interventions, 65% were accepted by the responsible physician.DRPs occurred frequently during the study period. Drug-drug interactions, drug choice and drug dosing problems represented the majority of the identified DRPs, necessitating targeted prescriber education interventions in these areas. There is a clear need for clinical pharmacists' involvement on the ward level to identify and rectify these frequently occurring and very costly problems.