During the last years, the importance of Traffic Safety Culture (TSC) for the improvement of road safety is becoming increasingly recognized. Greece is performing poorly in road safety among the European Union countries. The aim of this study is to present the methodology developed for the investigation of TSC of Greek drivers belonging to different socio-economic units. The methodology includes quantitative surveys among and qualitative interviews with professional drivers, private car and motorcycle drivers, drivers in Athens and on the island of Rhodes. Specially designed survey questionnaires and semi-structured interview guides were developed covering demographics, behavior at individual level and national level, paternalism, enforcement, accident causation and road safety outcomes to shed light on TSC at organizational and local level. The purpose of the qualitative interviews was for interviewees to highlight the main themes and questions in the survey, and to speak openly providing more information than the questionnaires allowed. Emphasis was given to concrete examples, potential influence of other road users on drivers and what affects common ways of driving and behaving in social groups at different levels. Overall, 503 private vehicle drivers and 202 professional HGV and bus drivers were surveyed, and 30 and 20, respectively, were interviewed.