Medication-related problems are common in hemodialysis (HD) patients. These patients often require 12 medications to treat 5 to 6 comorbid conditions. Medication-related problem research reports cannot be generalized to the entire HD population because data are obtained from single centers and limited numbers of patients. We conducted a pooled analysis to gain additional insight into the frequency, type, and severity of medication-related problems and extrapolated the data to the entire US HD population. Articles were identified through a MEDLINE search (1962 to March 2004). Seven studies were included in the analysis. Medication-related problems were categorized into the following 9 categories: indication without drug therapy, drug without indication, improper drug selection, subtherapeutic dosage, overdosage, adverse drug reaction, drug interaction, failure to receive drug, and inappropriate laboratory monitoring. A medication-related problem appearance rate was determined. We identified 1,593 medication-related problems in 395 patients (51.2% men; age, 52.4 +/- 8.2 years; 42.7% with diabetes). The most common medication-related problems found were inappropriate laboratory monitoring (23.5%) and indication without drug therapy (16.9%). Dosing errors accounted for 20.4% of medication-related problems (subtherapeutic dosage, 11.2%; overdosage, 9.2%). The medication-related problem appearance rate was 5.75e(-0.37x), where x equals number of months of follow-up (P = 0.02). HD patients experience ongoing medication-related problems. Reduction in medication-related problems in dialysis patients may improve quality of life and result in decreased morbidity and mortality. Pharmacists are uniquely trained to detect and manage medication-related problems. Pharmacists should be an integral member of the dialysis health care team.