The aim of the present study was to prepare and characterize controlled-release matrix tablets of Diltiazem hydrochloride using various viscosity grades of hydrophilic polymers and hydrophobic polymers in three different proportions were prepared by wet granulation method and subjected to in vitro drug release studies. The studies shows that formulation of drug with polymers like hydrophilic HPMC K4M >HPMC K15M >HPMC K100M and hydrophobic polymers like Eudragit RL100 >Eudragit RS100> Ethyl cellulose showed the drug release in decreasing order. Among that D1C which containing HPMC K100M with ethyl cellulose in the ratio of 1:2 showed the best controlled release of diltiazem hydrochloride. Thus the above study clearly indicated that diltiazem HCl may be formulated as Controlled release tablets using HPMC K100M with ethyl cellulose by wet granulation method which will provide continuous release of drug at a predetermined rate and for a predetermined time. Keywords: Controlled release, Matrix tablets, Diltiazem hydrochloride, Wet granulation method.