JL cross-sectional study of the prevalence ofrndental fluorosis among Nazareath higb school studentrnpopulation and determination of the concentration ofrnfluoride in tne water supoly of t he town was carriedrnout in June 1986 . Of the 4092 9th , l0th and 11thrngrades student population 1023 (25%) students '!Jerernselected f or dental examination and interview by thernprocess of random sampling method using t a bl e of ran domrnnumbers . Out of the 1023 s tud en t s , 821 (80 . 3%) respondedrnto t~e s t udy. Of the 821 , 334 (40 . 7%) are born i nrn~Iazareath , 58 (7.1%) are b orn in ':ionji , Koka , lolenchitirnand Hetehar a snd the remaining 429 students (52 . 2%) arernborn in othe r ol aces Rn~ a rri ved to live in Nazareathrna t di ffe r ent year of their ages. The prevalence ofrndental fluoro Gis a~ong the High School student populationrnis found to be 38 . 2% with no s tatistic a lly s ignifican trndiffer enc e betwe en the mal es (36 . 9%) and femal es ( 40 . 9%)rn(xrn2 = 0 . 77 , xrn2rn95 ( 1 d. f) = 3.84 , xrn2rn99 (1 d.f) = 6 .63,rnP ", 0 . 01 , P 0 . 05) . i.nd the preva l enc e among those bornrnand brought up in ~azR r ea th is 69 . 1% with significantrndifference when comnar ed to thos e who have come to livernin Nazareath at differ en t times of t heir agern(xrn2rn= 232 . 19, x2 99 ( ) d . Â£) = 11.34 , (p < 0 : 01) . There i srnalso sta tistically significant difference among therndifferen~ ege groups with the young er age gr oups thernpercent being high (xrn2rn= Yf . 22 , xrn2rn99 (~ d . fJ = 13 . 27 , P