Pillow basalts have been found in the Motagua fault zone of Central Guatemala. They are associated with pillow breccias and some hyaloclastites and exhibit the typical textures of alpinotype pillow lavas, in particular a variolitic rim with spherulitic varioles. Twelve chemical analyses show that these lavas are basalts with a composition showing a mildly spilltic trend. There is a good correlation between chemical composition and granularity; the fine-grained rim of the pillow, is, except in one case, poorer in Ca and richer in SiO₂ and Na₂0 than the center. These rocks are rich in well crystallized pumpellyite; they have been metamorphized into the pumpellyite- prehnite facies. They possibly represent a fragment of the El Tambor formation which has been incorporated into the serpentinite melange of the Motagua fault zone.