Abstract. Banks were among the pioneers in developing and implementing relationship marketing strategies, since they were between the first recipients of the radical changes that took place in global economy in recent years. This study is part of an ongoing research project, which among others, aims to develop an instrument to measure the outcome of the implementation of relationship marketing strategies. Field research was conducted among customers of Greek banks. Principal component analysis was then performed in order to identify latent factors among the questionnaire items. The results obtained were satisfactory, since 7 factors were extracted, which were labeled as relationship value, crisis management, personalized sales, customer focus, flexibility, communication quality and reliability. Moreover, regression analysis verified the significant explanatory power of the factors emerged over customer loyalty.