The El Nino events of 1982 and 1997 are the biggest ones in history. Both El Nino events resulted in decreased rainfall, particularly during the dry season of May-August. The 1997 El Nino caused a higher decrease in rainfall than the 1982 one. Consistently, in Java and Sulawesi the decrease in rainfall was higher compared to the national average in both 1997 and 1982. Since Java and South Sulawesi are major food producers (about 65 per cent of national food crop production), El Nino events could disturb national food security. In Kalimantan, the decrease in rainfall was relatively high during the 1997 El Nino, but quite low during 1982. On the contrary, Sumatera, Bali and Nusa Tenggara experienced a decrease in rainfall which was quite high in 1982 but relatively low in 1997. The study covers a wide range of topics such as an historical overview of El Nino induced abnormal weather, its impacts on major food crops, and a quantitive analysis of El Nino vulnerability. This study is useful to prepare strategic proposals for technologies, farm management and administrative policies to stabilize upland crop production and the farm economy leading to sustainable rural development in the region.