Novel organic electrically conductive organic fibers (ECFs) have been fabricated using a facile, economical and scalable technique by staining nonconductive fibers (both natural and synthetic) with a conductive ink composed of two intrinsically conductive materials, i.e., single walled carbon nanotubes (SWCNTs) and regioregular poly(3-hexylthiophene) (rr-P3HT). These organic ECFs exhibit low resistance of 0.50 k Omega cm(-1) with a conductive ink composed of 0.8 mg/mL of SWCNTs and 1.6 mg/mL of P3HT while maintaining the mechanical properties of the original fibers. These organic ECFs were characterized by resistance measurements, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy and stress strain measurements. Finally, the recording properties of the organic ECFs were examined by both electromyography and electrocardiography in terms of the signal-to-noise ratio, which was found to be similar and/or exceeded the data obtained by standard metal electrodes.