Resumo. The objective of this work was to compare the performance of two analytical techniques, flame atomic absorption spectroscopy (FAAS) and ultraviolet-visible spectroscopy (UV-VIS), in the determination of the silica content in lignocellulosic materials. The methods were tested in wood specimens of three trees of Apuleia leiocarpa (Vog.) Macbride. The results showed that both techniques present good performance, but the FAAS presents better precision, speed and operational simplicity. However, the application of the UV-VIS spectroscopy is justified by the fact of the acquisition and maintenance costs of an UV-VIS spectrophotometer are lower when compared to those of a spectrometer of atomic absorption. The use of the FAAS technique should just be chosen when the silica content is expected to be very low, once the UV-VIS spectroscopy, in those cases, does not present good precision.