In this study, a new electrochemical sensor based on magnetite graphene oxide/modified carbon paste electrode (Fe3O4–GO/CPE) was applied for determination of a cardiovascular drug, propranolol (PRO) in solution containing sodium dodecyl sulfate (SDS) as a surfactant. Results show that combination of modified electrode with surfactant addition, considerably increased electroanalytical signal for PRO determination and resulted to sensitive detection of PRO with linear range of 10–1500 μM, limit of detection of 4.5 μM and sensitivity of 166 μA mM–1. Applicability of this analytical method for detection of PRO in pharmaceutical formulations was studied and acceptable results obtained.