Aims This study aimed to apply the volatile organic compounds fromStreptomyces philanthiRL-1-178 (VOCs RL-1-178) as a fumigant to protect soybean seeds against the two aflatoxin-producing fungi in stored soybean seeds. Methods and Results The antifungal bioassay tests on potato dextrose agar (PDA) dishes showed that 30 g l(-1)wheat seed inoculum ofS. philanthiRL-1-178 exhibited total (100%) inhibition onAspergillus parasiticusTISTR 3276 andAspergillus flavusPSRDC-4. Identification of the VOCs RL-1-178 using GC-MS revealed 39 compounds with the most abundant substances being geosmin (13 center dot 75%) followed byl-linalool (13 center dot 55%), 2-mercaptoethanol (9 center dot 71%) and heneicosane (5 center dot 96%). Comparison on the efficacy of the VOCs RL-1-178 (at 30 g l(-1)wheat seed culture) and their four major components (100 mu l l(-1)each) on the suppression of the two aflatoxin-producing fungi on PDA plates revealed that the VOCs RL-1-178 as well as geosmin,l-linalool and 2-mercaptoethanol completely inhibited (100%) mycelial growth while heneicosane showed only 70 center dot 7% inhibition. Use of the VOCs RL-1-178 (30 g l(-1)) as a biofumigant on stored soybean seeds resulted in complete protection (100%) against the infection as well as complete inhibition on production of aflatoxin (B-1, B(2)and G(2)) (analysed by HPLC) by the two aflatoxin-producing fungi. Conclusions The VOCs RL-1-178 displayed strong inhibitory effects onA. parasiticusTISTR 3276 andA. flavusPSRDC-4 as well as inhibited aflatoxin (B-1, B(2)and G(2)) production. Significance and Impact of the Study These findings suggest that the VOCs RL-1-178 can be applied as a biofumigant to control the two aflatoxin-producing fungi on stored seeds products.