Background: Unseasonal rains beginning in 1995 damaged the maize and sorghum crops harvested in a few villages of the Deccan plateau in India. Human consumption of those grains resulted in a foodborne disease outbreak characterized by abdominal pain, borborygmi and diarrhea. Methods: A rapid epidemiological survey was conducted in the affected villages and a detailed house to house survey in selected villages. Results: People in 27 out of 50 villages surveyed were affected and disease was seen only in households and subjects consuming the rain damaged moldy sorghum or maize. The disease was self limiting. Diarrhea was reproduced in day old cockerels fed contaminated grains from affected households. All 20 sorghum and 12 maize samples collected from affected households had Fusarium sp. as the dominant mycoflora and contained fumonisin B₁ in the range of 0.14-7.8 mg/kg and 0.25-64.7 mg/kg, respectively. In contrast, samples collected from unaffected households had fumonisin B₁ in low level ranging from 0.07-0.36 mg/kg and 0.05-0.24 mg/kg, respectively. Conclusion: The higher water activity in the grains left in the field following harvest led to the production of high levels of fumonisin B₁ an consumption of such grains by humans resulted in the disease