Background: Heart transplantation (HTx) and implantable left ventricular assist systems (LVAS) improve outcomes in advanced heart failure but may be underutilized. We hypothesized that screening can identify appropriate candidates. Methods and results: The ScrEEning for advanced Heart Failure treatment (SEE-HF) study was a multicentre prospective study screening patients with existing cardiac resynchronization therapy (CRT) and/or implantable cardioverter-defibrillator (ICD) for ejection fraction ≤40% and New York Heart Association (NYHA) class III–IV, and subsequently for guideline-based HTx and LVAS indication. Of 1722 (mean age 64 ± 14 years, 26% women) patients screened at eight centres in seven European countries, 121 (7.0%) were eligible and 99 (5.7%; mean age 61 ± 10 years, 19% women) patients were enrolled for detailed assessment. Twenty-six of the 99 enrolled patients (26%) were eligible for either HTx or LVAD (18 eligible for HTx; 7 eligible for LVAD; and 1 eligible for both). Eleven patients were listed for HTx and three received an LVAS. Eligible patients were 61 ± 8 years and 19% women, whereas those actually receiving intervention were 56 ± 8 years and 8% women. Conclusions: Among patients with CRT and/or ICD, a minority have NYHA class III–IV heart failure and ejection fraction ≤40%. Among these, however, more than one-quarter have an unrecognized need for HTx or LVAS. When patients are offered intervention based on screening, many decline. Discrepancies exist between clinical and patient equipoise. Clinical Trial Registration ClinicalTrials.gov Unique Identifier: NCT00894387.