World Vision is calling for more money to tackle food shortages across the region, amid concern 33,000 children in Zimbabwe need urgent treatment for "severe acute malnutrition".
The organisation's workers claim a drought induced by the El Nino weather phenomena has hit the country particularly badly.
They warn harvests have been devasted and food prices have soared, leaving a third of Zimbabwe's population in need of aid.
Beatrice Mwangi, the World Vision Southern Africa region resilience and livelihoods director said: "Thousands of children in Zimbabwe and across Southern Africa are slipping into malnutrition and death.
"Many are not going to school due to hunger and this represents a big loss to the communities and countries across the region.
"If we do not see a positive response in funding, we may see even more children malnourished or dying."
17-year-old Clement Ndlovu who lives in rural Matobo and has been out of school for the past two years due to lack of tuition fees and food shortages said: "I'm one of many young people who have been out of school because of the prolonged drought.
"We now just stay at home waiting for someone to help us.
"We used to look after our grandparents' cattle and livestock but they are dying because the pastures are fast drying and there is no water for them as the rivers have dried up as well."