The technological properties of cotton fibers, such as upper half mean length, length uniformity, strength, and Micronaire fineness, and other characteristics such as percent lint and weight of one boll were studied in relation to four sampling methods, to evaluate whether the usual sampling procedure from the medium third part of the peant is representative of all the plant. The data obtained for usual sampling procedure were correlated with results from marked samples. This samples were composed by bolls of same age, obtained from flowers opened in the same day and subjected to the same weather conditions. Those bolls were harvested from the following parts of the plant: (i) lower, (ii) medium, and (iii) upper section. The results showed that the average of marked samples gave good correlation with the sample from medium section (ii), indicating to be the medium third representative of all the plant. The samples obtained by usual procedures gave better correlation with the average of marked samples. Also it was shown that the usual procedure may give better results than the average of marked samples, being more practical and with good precision.