Background: ECMO is a particularly scarce resource during the COVID-19 pandemic. Its allocation involves ethical considerations that may be different to usual times. There is limited pre-pandemic literature on the ethical factors that ECMO physicians consider during ECMO allocation. During the pandemic, there has been relatively little professional guidance specifically relating to ethics and ECMO allocation; although there has been active ethical debate about allocation of other critical care resources. We report the results of a small international exploratory survey of ECMO clinicians’ views on different patient factors in ECMO decision-making prior to and during the COVID-19 pandemic. We then outline current ethical decision procedures and recommendations for rationing life-sustaining treatment during the COVID-19 pandemic, and examine the extent to which current guidelines for ECMO allocation (and reported practice) adhere to these ethical guidelines and recommendations. Methods: An online survey was performed with responses recorded between mid May and mid August 2020. Participants (n = 48) were sourced from the ECMOCard study group—an international group of experts (n = 120) taking part in a prospective international study of ECMO and intensive care for patients during the COVID-19 pandemic. The survey compared the extent to which certain ethical factors involved in ECMO resource allocation were considered prior to and during the pandemic. Results: When initiating ECMO during the pandemic, compared to usual times, participants reported giving more ethical weight to the benefit of ECMO to other patients not yet admitted as opposed to those already receiving ECMO, (p < 0.001). If a full unit were referred a good candidate for ECMO, participants were more likely during the pandemic to consider discontinuing ECMO from a current patient with low chance of survival (53% during pandemic vs. 33% prior p = 0.002). If the clinical team recommends that ECMO should cease, but family do not agree, the majority of participants indicated that they would continue treatment, both in usual circumstances (67%) and during the pandemic (56%). Conclusions: We found differences during the COVID-19 pandemic in prioritisation of several ethical factors in the context of ECMO allocation. The ethical principles prioritised by survey participants were largely consistent with ECMO allocation guidelines, current ethical decision procedures and recommendations for allocation of life-sustaining treatment during the COVID-19 pandemic.