An ab initio calculation has been performed to study the hyperpolarizabilities of substituted octupolar triazines in the frame of a tensorial formalism. Electron correlation, solvent effect and frequency dispersion have also been explored. It is found that the impact of electron correlation is very important on the hyperpolarizabilities. Solvent effects on the beta values are significant and about the same at various approximation (HF, MP2, MP3, and MP4) levels. Dispersion effects are also important on the hyperpolarizabilities. Considered these effects, the calculated values are in agreement with the experimental results. (C) 2002 Published by Elsevier Science B.V.