Perilla seed meal (PSM) is a by-product of perilla seed oil extraction and a good source of bioactive peptides. In this study, the effects of heat, pH, and intestinal protease treatments on the antioxidant activity and stability of two antioxidant peptides (PAP1 and PAP2) were assessed and quantified; the stability was evaluated by measuring the 1,1-diphenyl-2-picrylhydrazine (DPPH) radical scavenging activity, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sul- fonic acid (ABTS) radical scavenging activity, and reducing power. The strength of the antioxidant effects of PAP1 and PAP2 was found to be reasonably well preserved relative to that of positive controls. Specifically, PAP1 and PAP2 maintained their antioxidant activity or exhibited only slightly decreased activity after heat treatment, with >76% activity retention. The antioxidant activities of PAP1 and PAP2 were lower than those of the controls under acidic and basic conditions but remained above 70% at all pH values except pH 12. Additionally, the antioxidant activity of both peptides remained above 66%, even after treatments of pepsin, chymotrypsin, and trypsin. Thus, the results indicate that antioxidant peptides from PSM protein hydrolysate are reasonably resistant to heat, pH, and intestinal proteases. Furthermore, these results demonstrate that antioxidant peptides derived from PSM hydrolysate exhibit high potential as natural antioxidant peptides for food and/or nutraceutical applications.