Introduction: It is true that the comparison of conventional and electronic cigarettes is a topic that has been discussed a lot and concerns both citizens and health professionals worldwide. The rates of smokers in Greece are high in combination with the fact that smokers are more likely to get seriously ill from covid-19, it was the reason to investigate this topic. Aims: To investigate the citizens knowledge and attitude about the electronic and conventional cigarette. Study Design: It was a comparative descriptive research. Place and Duration of Study: The questionnaires were given to citizens who lived in the prefecture of Achaia (one of the largest prefectures in Greece). The present survey was conducted between March and May 2020. Methodology: A questionnaire was developed with 28 questions. The Chronbach alpha reliability was .75. The sample consisted of 681 citizens. The statistical analysis was performed with SPSS 25 program. Results: The majority of citizens had very good knowledge (57.6%) while 20.3% had good knowledge. Most citizens were non-smoker (64.3%), they did not use electronic cigarette (91%) but they did try in the past (52.3%). Regarding electronic cigarette, they believe that it was not replaced the conventional, was not helpful for quit smoking and it was harmful as much as the conventional one. Finally, the cheaper price of e-cigarette contributes to its choice. Age, permanent residence and educational level significantly correlated with knowledge score (p<0.05). Conclusion: The majority of citizens were non-smokers while the conventional cigarette is still the first preference of the citizens. Although citizens' knowledge of conventional cigarettes and e-cigarettes was very good, it is necessary for health professionals to enrich their knowledge and inform citizens efficiently about smoking.