Electrically conducting fibers were prepared through in situ oxidative polymerization of pyrrole (Py) in the presence of peach palm fibers (PPF) using iron (III) chloride hexahydrate (FeCl 3. 6H 2 O) as oxidant. The polypyrrole (PPy) coated PPF displayed a PPy layer on the fibers surface, which was responsible for an electrical conductivity of (2.2 6 0.3) 3 10 21 S cm 21 , similar to the neat PPy. Electrically conductive composites were prepared by dispersing various amounts of PPy-coated PPF in a polyurethane matrix derived from castor oil. The polyurethane/PPy-coated PPF composites (PU/ PPF-PPy) exhibited an electrical conductivity higher than PU/PPy blends with similar filler content. This behavior is attributed to the higher aspect ratio of PPF-PPy when compared with PPy particles, inducing a denser conductive network formation in the PU matrix. Electromagnetic interference shielding effectiveness (EMI SE) value in the X-band (8.2-12.4 GHz) found for PU/PPF-PPy composites containing 25 wt% of PPF-PPy were in the range 212 dB, which corresponds to 93.2% of attenuation, indicating that these composites are promising candidates for EMI shielding applications. POLYM. COMPOS., 00:000-000, 2015.