Poly(o-toluidine) is a methyl-substituted analog of the well-known conducting polymer polyaniline (PANi). Recent reports have shown that PANi can be synthesized as uniform nanofibers with diameters less than 100 nm. This is easily achieved in aqueous acidic medium over a wide range of reactant concentrations. The nanoscale morphology of poly(o-toluidine), in contrast, displays a remarkable dependence on reactant concentrations. Scanning electron microscopy images show that at a monomer-to-oxidant ratio of 4:1, 0.04 M o-toluidine produces nanofibers similar to PANi. However, increasing the concentrations by a factor of 10 yields microspheres (~ 0.2 to 20µm diameter) with highly porous internal structure. UV-Vis and FTIR spectra of both morphologies are consistent with bulk poly(o-toluidine). Studies are underway in order to identify the transition point between fibrous and spherical morphologies.