Background Coronary pseudoaneurysms occur as a rare complication following drug-eluting stent implantation and have been reported to occur between one week to four years after implantation. Most of them remain in a stable state, but progression of pseudoaneurysms increases the risk of rupture and hemorrhagic cardiac tamponade. Case Report Here, we present a case of a 55-year-old patient, who developed a pseudoaneurysm of the proximal left circumflex artery after stent implantation of the left main, left anterior descending artery and left circumflex artery. Within less than one year the patient was readmitted to different hospitals due to cardiac decompensation and myocardial infarction. Thereby coronary angiography as well as CT-scans were performed and progression of the pseudoaneurysm could be documented. Interventional therapy was chosen due to high surgical risk of the patient. Implantation of a covered stent from the left main artery into the left anterior descending artery was chosen to treat the pseudoaneurysm, thereby silencing the chronical occluded left circumflex artery, followed by dilatation with non-compliant balloon. The patient has remained asymptomatic in a 6-months follow-up. Discussion Coronary pseudoaneurysm should be controlled with respect to progression and appropriate therapy can be chosen for treatment.