The preparation and performance of a disposable amperometric magnetoimmunosensor for the specific detection and quantification of human cardiac Troponin T is reported. The immunosensor design involves binding of streptavidin‐ magnetic beads to a specific biotinylated capture antibody and detection with a HRP‐labeled antibody. The resulting modified‐MBs are magnetically captured on the surface of a disposable gold screen‐printed electrode and the amperometric response obtained at −0.10 V upon addition of 3,3′,5,5′‐tetramethylbenzidine and H2O2 is used to monitor the affinity reaction. This methodology achieves a detection limit of 0.017 ng mL−1, a good selectivity and has been successfully tested with serum samples.