An attempt is made to understand the growth kinetics of carbon nanospheres (CNS) synthesized using a “green” technique. An aqueous solution of glucose, the precursor, was hydrothermally treated to produce porous CNS with homogeneous size distribution and smooth surfaces. The growth of CNS was studied by evaluating transmission electron microscope images as a function of hydrothermal reaction time and temperatures. Raman spectra revealed the presence of short-ordered graphitic nanostructures in an amorphous carbon matrix. FTIR spectroscopy confirms the carbonization of glucose and shows the presence of surface hydroxyl groups on CNSs. Based on various experimental observations it is proposed that the growth of CNSs is dictated by a reaction-controlled mechanism where long chain glucose-based oligomers bond to the CNS surface. The narrow size distribution and highly hydrophilic surface of these amorphous CNS makes them potential candidates for biomedical applications.