Ischemic stroke is a stroke with the highest prevalence (85%). Antiplatelet is one of the therapies to ischemic stroke patients at RSUD Prof. Dr. Margono Soekarjo Purwokerto. It may reduce the incidence of recurrent strokes, however this medicine may also increase the incident of Adverse Drug Reactions (ADRs) which can endanger the health of patients. The study aims to examine the side effects of the medicine in ischemic stroke patients at RSUD Prof. Dr. Margono Soekarjo. It was an observational study with retrospective data, then it was analyzed descriptively in the form of percentages. Data were taken from medical records and interviews through the Naranjo algorithm. The sample used was 90 patients. Adverse drug reactions in ischemic stroke patients were abdominal pain (43.44%), vomiting (36.67%), gastrointestinal bleeding (10%), and nausea (10%). Based on the findings of the study, the most common Adverse Drug Reactions in ischemic stroke patients with antiplatelet therapy were abdominal pain.