Background: In January 2021, the Diamondback 360 orbital atherectomy (OA) system received CE mark approval and became available in Europe. The first procedure in Europe was performed at the Thoraxcenter, Erasmus Medical Center, Rotterdam, the Netherlands. Aims: To report the procedural safety and efficacy of the initial experience with OA in a tertiary care institution in the Netherlands. Methods: Patients with de novo severely calcified coronary artery disease who were treated with intended invasive imaging-guided OA were included in a prospective single-centre registry. Device success, defined as less than 50% stenosis after OA, and procedural success, defined as successful stent implantation with less than 50% residual stenosis, were evaluated. Calcium debulking effects were assessed by invasive imaging. Safety was assessed up to 30 days after the index procedure. Results: Between February 2021 and June 2021, 29 patients with a total of 39 coronary arteries underwent OA. Target lesions were heavily calcified with a mean length of 32 mm and a calcium arc of 320 degrees. Invasive imaging was applied in all but one patient and 36 vessels. Superficial sanding was observed in almost all vessels (90%) and fracturing of deeper medial calcium in more than half of the vessels (63%), with a device success of 66% and procedural success of 94%. The mean stent symmetry index was 0.84, indicating good circular stent expansion. No primary safety events occurred during 30 days of follow-up. Conclusion: Our initial experience with OA for heavily calcified coronary lesions demonstrated favourable debulking effects and plaque modification, with high procedural success and clinical safety.