Sixteen corn samples collected from Indonesia were analysed for aflatoxins (AF), fumonisins (FM), trichothecenes and zearalenone (ZEA) using high-performance liquid chromatography and gas chromatography-mass spectrometry. AF were detected in 11 (69%) samples at a mean level of 119 ng/g (maximum 487 ng/g) and FM in all of the samples at a mean level of 895 ng/g (maximum 2970 ng/g). Deoxynivalenol (DON), nivalenol (NIV) and ZEA were each detected in two (12%) samples; 21 and 32 ng/g, 49 and 169 ng/g, and 11 and 12 ng/g, respectively. All of the AF-contaminated samples were co-contaminated with FM. Mycological study showed all of the AF-contaminated samples were infected with A. flavus/A. parasiticus, and the FM-contaminated samples were either infected with F. moniliforme (50%), F. proliferatum (12%), F. nygamai (6%) or F. decemcellulare (38%). Supportive mycological studies showed that Fusarium species isolated from Indonesian corn were capable of producing a mean level of 10,000 micrograms/g FM. Based on these results, the correlation between FM-producers and AF-producers on kernel infection and contamination of these mycotoxins in corn was discussed. This is the first report on the natural co-occurrence of AF and various Fusarium mycotoxins, including DON and NIV in corn from Indonesia, and also the first report on the natural occurrence of DON in corn from hot areas of Southeast Asia.