The cross-infection potential of Aspergillus flavus isolates obtained from groundnut, chilli, maize and pistachio was evaluated on these four host materials. The experiment was conducted during 2024-25 and 2025-26 using four isolates and four host materials in a completely randomised design with five replications. The time required for the first visible mycelial growth and sporulation along with host colonisation was recorded. First mycelial growth was observed within 1-4 days across replications, while first sporulation occurred within 2-6 days. Mean host colonisation ranged from 65.00 to 100.00 per cent across isolate host combinations. The groundnut, chilli and maize isolates recorded 100 per cent colonisation on groundnut, chilli and maize, while the pistachio isolate recorded 100 per cent colonisation on pistachio. The effects of isolate source, host material and their interaction on colonisation were significant at the one per cent probability level. The results demonstrated the ability of A. flavus isolates to colonise multiple host materials, although the extent and timing of colonisation varied among isolate host combinations.