Oregano (Thymbra capitata and Origanum vulgare) essential oils (EOs), cultivated and extracted in the South-East of Spain, were analysed by GC/MS to determine their composition. (E)-β-Caryophyllene (0.5-4.9%), thymol (0.2-5.8%), p-cymene (3.8-8.2%), γ-terpinene (2.1-10.7%) and carvacrol (58.7-77.4%) were determined as the main molecules. This characterisation was completed with enantioselective gas chromatography, where (-)-(E)-β-caryophyllene, (+)-a- pinene and (+)-β-pinene were determined as the main enantiomers. Antioxidant activity was evaluated positively by several methods, accounting for activity against free radicals and reducing power. Important inhibitory activity on lipoxygenase (LOX) and acetylcholinesterase (AChE) was observed supporting potential anti-inflammatory, anti-Alzheimer and insecticidal activities, mainly due to carvacrol. These properties support the potential use of oregano EOs as natural cosmetic and natural pharmaceutical ingredients.