Potassium and acid ferrierites were impregnated with boron species by wet and incipient wetness techniques. All samples display a medium-intensity band at 3,450-3,470 cm(-1) associated to Si-OH center dot center dot center dot O groups corresponding to boron-containing units. The 1,398-1,404 cm(-1) band assigned to the B-O stretching in BO3 units does not appear on boron-potassium-ferrierite prepared by wet impregnation. Catalytic performance during the linear butene skeletal isomerization was measured. At 300 degrees C, boron impregnated by incipient wetness technique on acid ferrierite reduces both linear butene conversion at a short time and isobutene yield in all time range. Boron-potassium-ferrierite prepared by wet impregnation has a suitable acidity to promote isobutene production. At 450 degrees C, this sample shows the best performance, being the isobutene yield 1.7 times higher than the acid-ferrierite one and reaching the highest isobutene selectivity (92%). This performance is maintained with time. Both isobutene yield and by-product distribution are strongly affected by temperature; dimer intermediates are formed. Finally, both kinds of hydroxyl groups corresponding to 3,466 and 3,635 cm(-1) bands influence the isobutene production whereas BO3 sites are inactive for this reaction.