Two dimethylallyltryptophan synthases, FgaPT2 and 7-DMATS, which catalysed the prenylation of L-tryptophan at positions C4 and C7, respectively, have been recently identified in Aspergillus fumigatus and proven biochemically. These enzymes were successfully used for the production of monoprenylated indole derivatives. In this study, we showed that C4,C7-diprenylated indole derivatives, e.g. 4,7-di-(dimethylallyl)-L-tryptophan, 4,7-di-(dimethylallyl)-L-abrine and 4,7-di-(dimethylallyl)-11-methyltryptophan, could be conveniently produced by tandem incubation of both enzymes. The structures of the isolated enzymatic products were elucidated by NMR and MS analyses. High conversion yields of up to 93% were achieved by an incubation sequence of FgaPT2 followed by 7-DMATS. The results reported in this study demonstrated the potential of secondary metabolite enzymes as promising tools for the production of designed compounds.