In this work, we study the oxidative state of nine taxa of aquatic insects [Serratella ignita (Poda, 1761), Ephemera danica Müller, 1764, Crocothemis erythraea (Brullé, 1832), Dinocras cephalotes (Curtis, 1827), Perla bipunctata Pictet, 1833, Isoperla morenica Tierno de Figueroa & Luzón-Ortega, 2011, Notonecta maculata Fabricius, 1794, Gerris sp., and Hydropsyche sp.] in order to determine the relationships between this state and the biological and environmental characteristics of the species studied. The studied taxa are all in the same life cycle stage (nymph/larva), and many of them have different maximum life span potentials. We assess the antioxidant capacity through the determination of the trolox-equivalent antioxidant capacity, the ferric-reducing/antioxidant power and the activity of the antioxidant enzymes catalase, DT-diaphorase, glutathione peroxidase, glutathione reductase, glutathione transferase, superoxide dismutase and glucose-6-phosphate dehydrogenase. Furthermore, to determine the oxidative damage, we examine thiobarbituric acid reactive substances, free malondialdehyde, protein-bound malondialdehyde, total hydroperoxides, and protein hydroperoxides. In summary, we can consider that having predatory feeding habits, having a long-life cycle and living in permanent streams with cold, well-oxygenated waters are related to a proper oxidative state in the insects that we studied. On the other hand, non-exclusive predator species living in temporary streams with warm and poorly oxygenated waters with a short life cycle have a worse oxidative state. Thus, the oxidative state of each species could be defined by an interaction of biological and autecological factors, for which the relative importance is difficult to assess.