Purpose To address the lack of prospective data on the real-life clinical application of trans-arterial radioembolization (TARE) in Europe, the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) initiated the prospective observational studyCIRSE Registry for SIR-Spheres (R) Therapy (CIRT). Materials and Methods Patients were enrolled from 1 January 2015 till 31 December 2017. Eligible patients were adult patients treated with TARE with Y90 resin microspheres for primary or metastatic liver tumours. Patients were followed up for 24 months after treatment, whereas data on the clinical context of TARE, overall survival (OS) and safety were collected. Results Totally, 1027 patients were analysed. 68.2% of the intention of treatment was palliative. Up to half of the patients received systemic therapy and/or locoregional treatments prior to TARE (53.1%; 38.3%). Median overall survival (OS) was reported per cohort and was 16.5 months (95% confidence interval (CI) 14.2-19.3) for hepatocellular carcinoma, 14.6 months (95% CI 10.9-17.9) for intrahepatic cholangiocarcinoma. For liver metastases, median OS for colorectal cancer was 9.8 months (95% CI 8.3-12.9), 5.6 months for pancreatic cancer (95% CI 4.1-6.6), 10.6 months (95% CI 7.3-14.4) for breast cancer, 14.6 months (95% CI 7.3-21.4) for melanoma and 33.1 months (95% CI 22.1-nr) for neuroendocrine tumours. Statistically significant prognostic factors in terms of OS include the presence of ascites, cirrhosis, extra-hepatic disease, patient performance status (Eastern Cooperative Oncology Group), number of chemotherapy lines prior to TARE and tumour burden. Thirty-day mortality rate was 1.0%. 2.5% experienced adverse events grade 3 or 4 within 30 days after TARE. Conclusion In the real-life clinical setting, TARE is largely considered to be a part of a palliative treatment strategy across indications and provides an excellent safety profile.