A magnetostratigraphic investigation on a Middle-Late Triassic section outcropping at Cuevas de Ayllon (westernmost margin of the Iberian Ranges, Spain) has been performed. The section mostly consists of a thick sequence of interbedded mudstones and sandstones. The age of the sampled formation has been established as Ladinian-Karnian on the basis of palynological assemblages. 123 samples were subjected to a progressive thermal demagnetization up to 680 °C.A multicomponent magnetization behaviour has been observed. The characteristic component could be isolated from 575-620 °C up to 680 ° C, in 74 samples showed both polarities and allowed to define a consistent magnetic zonation. The data presented will contribute to the construction of a standard polarity scale for the Triassic time span