Spherical morphology of carbon with 150-400 nm size is produced by sonication (480 kHz, 2.5W) of toluene with water under ambient conditions. Medium range of frequency and weak power of ultrasound is found to be the appropriate conditions for preparing the carbon spheres. Morphological and structural analysis of the product is carried out with TEM, SEM, elemental analysis, TGA, and FT-IR spectroscopy. (C) 2013 Elsevier B.V. All rights reserved.