Several aspects of the variability of the physical and ehemical properties of leather are discussed in conection with sampling problems of this material, such as selecting the most representative sampling area and the determination of sample size. The solution for these problems applying statistical criteria require in each case, to know the values of the respective variability parameters. The present state of this subject is discussed. The procedure to assess the amount of items that make up a sample taking into account the standard deviation and the specified limits for the first and second class errors is described. A practical example is given.