Background: Percutaneous coronary intervention (PCI) techniques are evolving, but the management of coronary calcification remains a major challenge for interventional physicians, especially left main coronary artery (LMCA) calcification. Intravascular lithotripsy (IVL) is a relatively new but promising modality for treating calcified lesions, [1] So to date, calcium modification strategies could include any combination of IVL and/or RA with high pressure non-compliant balloon and cutting balloon inflations. [2] PCI of LMCA deep calcific disease (LMCA-PCI) is challenging and its large lumen is sometimes unsuitable to RA. Furthermore, there was no large randomized controlled trialsin unprotected calcified LMCA IVL. Methods: Nine consecutive patients with unprotected left main disease (mean syntax score of 33.5) underwent IVUS-guided IVL before stent implantation. The procedural success rate was 100% without intraoperative complications (death, stent thrombosis, target vessel revasculation). Results: Nine patients underwent unprotected LMCA IVL (11.1% of ostium 22.2% of shaft 66.7% of bifurcation).66.7% were male and the mean age was 65.3 ± 9.69 years. 55.6% of patients presented with nstable agina (UA) ,22.2% with acute ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction(NSTEMI)respectively .100% of patients had IVUS imaging. There was a significant gain within LMCA in minimal lumen area (MLA) post PCI of 100% following IVL,Minimal stent area (MSA) of LMCA was most satisfactory post PCI. There were no death, angina pectoris, bleeding, embolism, and recurrent myocardial infarction during the procedureas well as at 30 days follow-up. Conclusions: IVUS-guided intravascular lithotripsy as an adjuvant to LMCA-PCI appears to be deliverable effective and safe.