The role of teachers is very important for the educational utilization of Computational Thinking (CT) and its integration in education. As with any innovation, CTs' successful integration considerably depends on the perceptions, beliefs and attitudes of the teachers who will be asked to implement it. The study of these characteristics, concerning Computer Science (CS) teachers in Greece, was the objective of a survey research, theoretically supported by the Theory of Reasoned Action (TRA) and the Technology Acceptance Model (TAM). Findings reveal intense interest of participants on CT and their willingness to participate in professional development programs. Participants also reveal misconceptions of CT and negative attitudes toward its integration in education, that require further study and discussion. The researchers propose directions for the design and implementation of appropriate teachers training programs, while the findings can be exploited to support any effort of integrating CT in education.