Aceclofenac sodium a novel NSAID used in the treatment of rheumatoid arthritis, frequency of administration may cause certain GI-adverse effects. The purpose of the present research work was to develop sustained release matrix tablets of aceclofenac sodium by wet granulation technique using different concentrations of locust bean gum (LBG) and hydroxyl propyl methyl cellulose (HPMC-K15M) as drug release controlling polymer matrices and different concentration of Pharmatose 200M as diluent. The solubility studies of aceclofenac were conducted to select suitable dissolution media. The drug excipients mixtures were subjected to preformulation by FTIR, DSC and XRPD studies. The different in-process and finished product quality controlled tests of the formulations were evaluated. Invitro drug release potential was estimated in simulated gastric fluid pH1.2 for initial 2h and simulated intestinal fluid pH 7.4 at the end 12h studies. While increasing the concentration of polymer diluent ratio significantly affects physicochemical properties of tablets and found within the limits. The release of drug from the tablets in pH1.2 is negligible. Under neutral conditions the tablets will swell and the release of drug in a sustained manner, exhibited Higuchi model kinetics followed to Korsemeyer and Peppas kinetics and shown the diffusion co-efficient (n) values in the range of 0.5810 to 1.185. This indicates, the drug release from matrix tablets by both diffusion and erosion mechanisms followed by super case-II transport. The entire process is feasible in an laboratory scale and demands pilot study