The present research was conducted in two phases. At the first stage, research was aimed at determining the epidemiology of smoking in Ahvaz government organizations personnel, and the second stage was launched to compare the efficacy of the following cessation methods: Behavioral, behavioral-instructional and behavioral-nicotine gum. Research methods of the first and the second stages of this study were, respectively, field and experimental approaches. The target population of the first stage, consisted of male and female personnel of various government organizations of Ahvaz city. The epidemiology sample consisted of 1334 subjects randomly selected from 26 organizations. Cessation sample consisted of 135 male subjects randomly selected from smokers who volunteered for cessation. Subjects were assigned randomly to the experimental and control groups, forming the following five groups each consisting of 27 subjects: 1) Behavioral, 2) Behavioral-instructional, 3) Behavioral-nicotine Gum, 4) Placebo and 5) Waiting list. the epidemiological findings showed that 23% of male personnel and 1.2% of female personnel were smokers, and each one of them, on the average, smokes 9 cigarettes a day. Furthermore, the mean age for turning to smoking was 20.9 years. Data analysis of the cessation stage showed no significant difference between behavior therapy and placebo groups. Behavioral-instructional and behavioral-nicotine gum groups were more effective than behavioral, placebo and waiting list groups.