Self-emulsifying drug delivery system (SEDDS) is an isotropic mixture of drug, oil, surfactant and co-surfactant which spontaneously forms emulsion in aqueous environment under gentle agitation. Many drugs are lipophilic in nature making them difficult for oral delivery as the GI environment is aqueous in nature. The objective of present work was to develop and evaluate the SEDDS of Aceclofenac using oleic acid as oil, tween 20 as surfactant and PEG 400 as  co-surfactant. Compatibility studies showed no interaction between drug and excipients used. Ternary phase diagram was constructed to optimize the formulation. Formulated SEDDSs were evaluated for drug content, zeta-potential, robustness to dilution, globule size and in-vitro drug release. Globule size were between 151.1-182.3 nm and spherical in shape. In-vitro drug release study revealed that the drug release form the formulated SEDDSs were faster when compare to pure drug and marketed product. Formulation S6 showed the highest drug release i.e. 91.71% within 25 m. Formulations were stable during testing period of 3 months. From this work, it was cleared that the SEDDS of Aceclofenac was found to be significant in terms of releasing of the drug as compare to pure drug and marketed product.