The ¹⁰Be/⁹Be ratios in marine sediments samples from the Southern Chile Trench have been measured using accelerator mass spectrometry (AMS). The samples were measured at the TANDAR accelerator, where the discrimination of the ¹⁰Be radionuclides was achieved by means of a passive absorber in front of an ionization chamber. This setup along with the high voltage available, provided a complete suppression of the ¹⁰B isobar interference. The obtained values for the ¹⁰Be concentrations, of the order of 10⁹ atoms/g, are the first ¹⁰Be measurements from the Southern Chile Trench and offer an excellent tracer to quantitatively study the recycling of sediments in Andean magmas.