Evolution Teaching (ET) among in-service teachers in Greece was examined in an attempt to evaluate their Pedagogical Content Knowledge. Evolution teaching is a problematic issue. For this purpose, we constructed a questionnaire that was distributed to the target population and to which 181 teachers responded. We used quantitative method to determine factors that may characterize the ET milieu and which of the factors of PCK apply or not to ET. Our research finds that Biology teachers although strive to teach evolution, face specific difficulties due to lack of PCK. The research results may be useful when organizing and implementing professional development programs of teachers on ET.