The United Nations children's agency, UNICEF, says at least 130,000 children in Ethiopia are suffering from severe malnutrition.
It says the number is likely to rise in the next two months.
The high levels of malnutrition are being blamed on drought, late rains and delays in distributing aid.
Claudia Hutsperth from UNICEF's global emergency response team in Ethiopia has described the situation as horrifying.
"I think the situation's quite concerning," she said.
"We've got it earlier, much earlier than in the past crises so we're on the upswing in terms of increasing levels of malnutrition.
"I think the numbers of children that are affected is horrifying and I think we're going to see it getting worse over the next couple of months."
ABC News Online