Microporous silicoaluminophosphates SAPO-5, SAPO-11 and SAPO-40 have been tested as solid acid catalysts in the dehydration of xylose into furfural (FUR) under biphasic aqueous-organic conditions, at 170 degrees C. For all materials, no decrease in catalytic activity is observed after three consecutive recycling runs. Furfural yields at 4 h using SAPO-11 (34-38%) are comparable with that for HMOR zeolite with Si/Al similar to 6 (34%), under similar reaction conditions, while H2SO4 (0.03 M) gives 2% FUR. Complete xylose conversion is reached within 16-24 h, with furfural yields of up to 65%. Bronsted and Lewis acidity of the silicoaluminophosphates was determined through FTIR analysis of adsorbed pyridine, and tentatively correlated with the catalytic performances.