Calcium hydroxide [Ca(OH)z], a by-product of acetylene production and calcium carbonate (CaCO3) were evaluated as liming sources for Bayamon soil (Typic Haplorthox), the most important soil series used for pineapple production. The pineapple variety Smooth Cayenne was used as the test crop. Three soil samplings were performed at two depths, 0-20 and 20-40 cm. The first sampling was performed a month after the liming materials were applied. The other two samplings were performed at four and seven months. The industrial by-product was as effective as calcium carbonate in neutralizing soil acidity.