Zircon U Pb isotope dating of the Capo Spartivento Orthogneiss, proposed as a possible Precambrian basement of southern Sardinia, shows that this rock is Caledonian in age. Conventional multi-grain analyses yield an imprecise age of roughly 480 Ma, and ion-microprobe analyses of cores of single grains yield a consistent age of 449 Ma. Though some inherited grains of Proterozoic age are present in the zircon population, they are neither abundant nor consistent with Caledonian growth of new zircons within an older protolith. ?? 1989.