Background: With respect to the prevalence of head louse infestation and its known complications, the present study was conducted over the school-aged children in Shahriar in 1993 with the aim of identifying the infestation rate of head louse and the effects of several pediculocides such as Coop ex, Ectopar, and Cit. Materials and methods: First of all, in a descriptive study, 1921 children were randomly selected and observed for the detection of head louse at different stages of development. Then, in the second phase a clinical trial was performed on 48 infected children. They have been randomly selected out of 304 infected individuals and were treated with Coopex, Ectopar, or Cit. They were reexamined after a week. Results: The total infestation rate of 15.8% was achieved of which 8.2% were males and 24.3% were females. In females, long hair has increased the chance of infection by 2.4 times. Coopex powder (containing permethrin), Ectopar shampoo (containing gamma benzene), and Cit shampoo (containing pyrethmm) resulted in disinfecting of head louse in 18.8%, 56.2%, and 93.7% of the cases, respectively (p<0.0005). Conclusion: Further studies are strongly recommended in other parts of Iran. With respect to pediculocides- resistant head louse, employing stronger materials should be investigated.