Blends (10 and 20%, w/w) of black cumin oil (BCO) and coriander oil (CO) with sunflower oil (SFO) were formulated. Oxidative stability (OS) and radical-scavenging activity of SFO and blends stored under oxidative conditions (60C) for 15 days were studied. By increasing the proportion of BCO and CO in SFO, linoleic acid content decreased, while oleic acid content increased. Progression of oxidation was followed by measuring peroxide value (PV), conjugated dienes (CDs) and conjugated trienes (CTs). Inverse relationships were noted between PV and OS at termination of storage. Levels of CDs and CTs in SFO and blends increased with an increase in time. SFO : BCO and SFO : CO blends gave 8–18 and 22–32% inhibition of DPPH• radicals, respectively. OS of oil blends was better than SFO, most likely as a consequence of changes in fatty acids' and tocopherols' profile, and minor bioactive lipids found in CO and BCO.