The prizes were awarded to the winners at a ceremony hosted by the Japanese IE-NO-Hikari Association in presence of the country's and foreign cultural officials along with the jury.
Hamed Tavassoli, 6, won the silver medal, Sahar Zarei, 11, got the bronze medal and Fatemeh Zare, 11, got the plate of honor, the Islamic republic news agency reported.
The Japanese Association had received 51,918 pictures by children from 68 countries in 2008.
The eligible participants were among six- to eleven-year- old children being free to choose the theme of their paintings.
IE-NO-Hikari Association works hard to foster cultures of rural villages through publication of books including "IE-NO-HIKARI" magazine as well as various cultural activities.
As a part of its diverse activities, the IE-NO-HIKARI Association has held the "World Children's Picture Contest" since 1993, in hope that the contest would create amity and friendship among children all over the world and help develop children's personality.