Spectrophotometric micro determination of allopurinol (ALP) via charge-transfer formation is described. This includes the utility of some $pi$-acceptors such as 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 3,6-dichloro-2,5-dihydroxy-p-benzoquinone (p-CLA) for estimation of ALP drug (act as $grave{e}$-donor). These reactions are applied for determination of ALP in its pharmaceutical preparations coming from different companies. Elucidation of the chemical structure of the solid CT complexes formed via reaction between drugs under study and $pi$-acceptors, using elemental analyses (C, H, N), I. R., $^1H$ NMR and mass spectrometry.