Detailed mechanical analyses were made in 27 agricultural limestones and in one slag, with commercial grades, which are used as soil amendments. The mechanical analyses were made by wet sieving with 9 standard sieves n.° 10, 20, 30, 40, 50, 70, 100, 140, and 200 (U.S.B.S. sieve number). To compare and interpret the particle distribution of sieve analyses, simple statistical criteria were utilized (first and third quartiles, sorting coefficient and quartile geometric standard deviation) and graphic representation was made in a mono log plot. Some samples showed great variation in fineness but most of the agricultural limestones have similar degrees of fineness, i. e., 20-30% particle diameter larger than 0.8 mm (sieve n.° 20) and 25-35% diameter smaller than 0.15 mm (sieve n.° 100). The results demonstrated also that samples have maximum selection for coarse particles. In most of the samples the coarse particles were represented by diameters larger than 0.3 mm (sieve n.° 50) in a proportion which varies from 50 to 60%.