Appreciation of the normal position of thehila is essential in screening and diagnosis of the diseases of the chest. many authors assessed the hilar position in normal adults using PA chest roentgenogram. however there have been no previous publications regarding consolidated assessment of various measurements, The authors carried out the present study to evaluate various hilar measurements including hilar points, hilar distances, difference between both hilar heights, hilar height ratio, and the relationship between the level o9f the clavicle and hila on the 500 normal PA chest roentgenograms (247 men and 253 women, age raging from 17 to 75 years). 1. Hilar points : 1) On midaxillary line9range; level of rib): 2) On posterior intercostal position (range ; order of rib): {{{{ }}{{male }}{{female }}{{total }}{{left }}{{5$frac{1}{2}$-7$frac{1}{2}$ }}{{5$frac{1}{2}$-8 }}{{5$frac{1}{2}$-8 }}{{right }}{{6-8 }}{{5$frac{1}{2}$-8$frac{1}{2}$ }}{{5$frac{1}{2}$-8$frac{1}{2}$ }} }} 2. Hilar distances(mean$pm$SD; cm): {{{{ }}{{male }}{{female }}{{total }}{{left }}{{5.3$pm$0.4 }}{{5.0$pm$0.4 }}{{5.1$pm$0.4 }}{{right }}{{4.6$pm$0.5 }}{{4.2$pm$0.4 }}{{4.4$pm$0.5 }} }} The left hilar distance was greater than the right in 94 %, equal in 4%, and less in 2%. 3. Sum of both hillar distance(mean $pm$ SD ; cm); male 9.9$pm$0.7 female 9.2$pm$0.6 total 9.5$pm$0.8 The distance was significantly greater in men than in women(P<0.01). 4. Difference between both hillar heights(mean $pm$ SD; cm): male $1.5pm$0.6 female 1.2$pm$0.5 total 1.3$pm$0.6 The left hilar point was higher than the in all cases(range was 0.1-3.1 cm). 5. hilar height ratio(%): {{{{ }}{{right($leq$$frac{1}{2}$) }}{{left(>$frac{1}{2}$) }}{{male }}{{90.7 }}{{92.3 }}{{female }}{{92.1 }}{{95.7 }}{{total }}{{91.4 }}{{94.0 }} }} 6. correlation between the levels of the clavicle and hila: Hilar levels had significant correlation with clavicular levels; the lower the clavicular level, the lower the hilar level. {{{{ }}{{male }}{{female }}{{total }}{{left }}{{4-6 }}{{4-6 }}{{4-6 }}{{right }}{{4-7 }}{{4-7 }}{{4-7 }} }}