A multiple drop-casting method of growing the ultralong dibenzo-tetrathiafulvalene (DB-TTF) micro/nanowire arrays has been developed which has the success ratio as high as 94%. This method enables the arrays with a length over a few hundreds of micrometers to locate between droplets with the definite orientation. The width of the micro/nanowires is controlled via tuning the concentration of DB-TTF solution in dichloromethane. The large-scale arrays can be grown onto Si, SiO₂, glass, and the flexible polyethylene terephthalate (PET) substrates. These results show the promising potential of this facile solution-based process for the growth of the high-quality organic micro/nanowires, the fabrication of high-performance and flexible devices, and the fabrication of controlled assemblies of nanoscale circuits for fundamental studies and future applications.