The purpose of this study   was  measuring concentration of fluoride  in
   drinking water in  Hamadan and Bahar cities, in west of Iran.

          By a pilot study sample size for  Hamadan and Bahar were estimated
   120 and 30,  respectively. The results were compared with Iranian Standard.
          The results showed that concentration of fluoride in drinking water of 
   Hamadan and Bahar were  0.198 and 0.6  mg/lit, respectively, which were
   less than the standard limit. The Shefe statistical test showed that  the
   concentrations of fluoride  in summer is less than others season  and the
   difference was statistically significant (P < 0.001 ) .

          Finally, it can be concluded that the concentrations of fluoride  in
   drinking water of  Hamadan and Bahar cities are  less than the standard
   limit, especially in summer. To  solve  the problem, it is recommended  to
   inject  sodium fluoride in drinking water of Hamadan and Bahar, 
   particularity  in summer.