We report a method for the fabrication of phthalocyanine particles with dimensions in the nanoscale regime. Phthalocyanines are of particular interest as reversed saturable absorption-based optical limiters. By fabricating phthalocyanine particles of nanometer sizes, we found intermolecular effects to strongly influence the linear and nonlinear optical properties. Linear optical studies, including absorption and emission spectroscopy, were used to investigate the interactions between the molecules inside the particles. The Z-scan technique was employed to examine the optical limiting effects in phthalocyanine nanoparticles compared to solutions of the corresponding molecules. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) studies were performed to further investigate the particle structure. Furthermore, X-ray diffraction measurements were made to probe the molecular alignment in the nanoparticle.