An oral sustained release matrix tablet of Theophylline HCl for up to 8h was developed using a binary mixture of polyehylline glycol (PEG 4000 or 6000) and polyvinyl acetate (PVAc) by hot melt granulation technique. Technological characterization (mean weight, diameter, thickness, hardness and swelling) was carried out and in vitro drug release behaviour was measured using the SUP paddle apparatus. The effect varying the PEG-PVAc ratio, as well as the drug-polymer matrix ratio, was evaluated. The results of controlled release tests showed that the amount of drug release is decreased with increasing the proportion of PVAc. Moreover, the release rate of drug decreased as the amount of drug loaded in the matrix increased. DSC and FTIR studies indicated the apsence of any significant chemical interaction between the drug the the polymers. Data fitted to Korsmeyers- Peppas equation indicated an Anomalous non-fickian transport suggesting that the drug release is mainly diffusion- erosion mechanism.