Abstract: The investigation was carried out by the addition of variable percentages (0, 2, 4, 8 and 12%) of either Aluminum Stearate (AS) or Dioctyl Sodium Sulphosuccinate (DOSS) in Glycerol Monostearate (GMS)-based suppositories of Diclofenac Sodium (DS). DS suppositories of GMS base were prepared using AS and DOSS separately in different formulations by pour moulding method. Dissolution studies were carried out in USP Dissolution Tester using phosphate buffer (pH 7.4) as the dissolution medium maintaining the temperature at 37±2°C. The effects of AS and DOSS were evaluated on the release rate of DS from the GMS-based suppositories. The hydrophobic nature of GMS retarded the drug release markedly, while the inclusion of increasing percentage of AS and DOSS in GMS-based suppositories enhanced the release rate of DS to a considerable extent. Throughout the investigation, the release patterns in both cases were found to be square root of time dependent; indicating diffusion type of drug release. Formulation of DS suppositories with 12% DOSS gave sustained drug release profile. The stability studies of the DS suppositories containing 12% as well as DOSS have proved these formulations to be stable dosage forms.