The Covid-19 pandemic reveal the need for structural reforms in various economic sectors including the banking sector. In Greece the banking sector needs to promote structural reforms promoting new products and services or improve existing ones to improve contactless transactions. The purpose of the paper is to explore the determinants (in terms of demographic, personal and behavioral factors) that are affecting the use of mobile banking during the Covid-19 pandemic in Greece. A multiple logistic regression and a structural equation model analysis are employed, in conjunction with confirmatory factor analysis, based on a proposed extended technological acceptance model (TAM). The data derived from a field survey on 617 users and non-users of mobile banking, using an appropriately-constructed questionnaire. The results showed that the demographics as well as the personal and technology acceptance factors contributed significantly to the adoption of this form of online banking in Greece. From the extended TAM model, perceived usefulness, perceived ease of use, perceived risk, hedonic motivation and social influence were found to have a significant impact on the use of mobile banking. Furthermore, perceived awareness combined with subconscious factors such as personal characteristics of Greek consumers play an important role. This is the first study for Greece, to the best of our knowledge, which examines the determinants affecting the use of mobile banking both in terms of consumers' perceptions and attitudes during a period where contactless transactions became necessary in the everyday life of consumers worldwide.