In the present report we describe a 70-year-old woman after antimitotic stent implantation who developed an allergy to clopidogrel. We monitored her platelet activity while on different drug regimes and at different time points during the allergic reaction. Tests showed incomplete platelet inhibition by acetylsalicylic acid and clopidogrel (dual antiplatelet drug resistance) during the acute allergic reaction with gradual improvement together with patient clinical status.