Many drugs are known to prolong QT interval which increases the risk of development of ventricular tachycardia and cardiac arrest. The majority of sudden cardiac deaths are caused by acute ventricular arrhythmia following repolarization disturbances. An important risk factor for repolarization disturbances is use of QT prolonging drugs. Drug interactions also play a clinically significant role in the development of QT prolongation substantially, in patients receiving multiple drugs that are prone to prolong QT interval. The present case study reports two consecutive QT prolongation events associated with drug-drug interactions in a patient during his hospital stay. A 63-years-old Asian male patient was being treated for his complaints of breathlessness, uneasiness, chest discomfort and palpitation (baseline QTc being 457 msec). During his treatment, he developed QT prolongation (QTc=494 msec) suspected to be the result of concomitant use of levofloxacin, ondansetron and ivabradine; QT prolongation reduced after discontinuation of the suspected drugs. In the same patient, during the later course of therapy, a concomitant use of amiodarone and fluconazole caused QT prolongation (QTc=536 msec) again. This complication is best approached with immediate discontinuation of interacting drugs and considering their alternatives. Knowledge enhancement regarding QT prolonging drug combinations and rapid ECG monitoring while using those combinations will help circumvent such adverse events.