Single event effects are due to ionizing particles impinging on sensitive circuit regions, directly or as a by-product of nuclear reactions. Atmospheric neutrons originating from the interaction of cosmic rays with the outer layers of the atmosphere, alpha particles from radioactive contaminants at sea level, and heavy ions in space continuously hit electronic devices, causing a plethora of effects, some of which are governed by the properties and geometry of the dielectric layers used in the struck devices. This contribution will review these effects, focusing first on the thin gate dielectrics used in complementary metal-oxide semiconductor circuits and then on tunnel oxide of floating-gate memories. (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3054271]