The incident occurred in Kamleshwar School in Pernem, 25 km from here.
"The children are in hospital and their condition is stable," the education department official said.
The incident comes less than two weeks after 23 school children in Bihar's Saran district died after eating contaminated food.
On July 19, 20 primary school students were admitted to hospital after some of them fell ill after a mid-day meal at a school in Ponda in eastern Goa. Students of a school in Canacona in south Goa were hospitalized on June 23 after eating mid day meal.