Study Design and Procedures Two hundred regular smokers, (not willing to quit) will be recruited in our center following placement of advertisements in local newspapers and radio/TV network. At baseline, participants will be randomized into three separate study groups. Fifty participants randomized in study group A will receive a "Personal Vaporizer electronic cigarette" and 24-weeks supply of e-liquid (active group); fifty subjects in study group B, 24-week supply of "Cigarette-like Electronic Cigarette" (active group); one hundred participants in study group C will continue usual smoking (control group).