Palladium (Pd) dendrites on carbon black support were synthesized by a simple template/surfactant-free electrochemical deposition. In comparison to Pd spherical deposit obtained on non-activated carbon, Pd deposited on an electrochemically activated carbon displayed a dendritic morphology with increased electrochemical surface area and showed enhanced catalytic activity for formic acid oxidation. The effect of electrochemical activation and deposition cycles were studied in relation to the growth and morphological features of Pd deposit. Scanning electron micrographs and X-ray diffraction studies showed a transition in Pd morphology from spheres to dendrites when the carbon support was subjected to varying cycles of electrochemical activation, prior to Pd deposition. Raman and X-ray photoelectron spectra results showed that the defects induced during electrochemical activation on carbon played a major role in tailoring the Pd morphology.