Core–shell nanocomposites of polyaniline and carbon black (PAni/CB) were electrochemically synthesized in acidic aniline and carbon black suspension. SEM and TEM observations reveal that the PAni synthesized in HClO 4 media exhibits one-dimensional (1D) growth and results in a porous PAni deposit constructed by coralloid interlinking branches having about 2 μm average diameter. In contrast, the existence of CB suspension produces rod-like PAni/CB core–shell nanocomposites, and decreases the average diameter to nearly 200 nm. XRD and Raman spectroscopy were employed to characterize the as-obtained CB powders, PAni and PAni/CB nanocomposites. Measurement of electric conductivity shows that incorporation on CB particles during electrochemical synthesis increased the obtained conductance.