Material collected in a field trial conducted in Dark Red Latosol (Typic Euthror-thox) was used to study dry matter and macronutrients accumulation in two cassava cultivars (Branca-de-santa-catarina and IAC-Mantiqueira). Plants received a uniform fertilization of N, P(2)0(5) and K2O of 40, 80 and 60 kg/ha, respectively as ammonium sulfate, simples superphosphate, and muriate of potash; N was top dressed 60 days after the sprouting. Samples were taken at six occasions during the growing season, with an interval of sixty days between each sampling. The plants were divided into roots, leaves and stems and each part was analysed for N, P, K, Ca, Mg and S. The results showed that: a) The period of greatest dry matter accumulation was between 120 and 180 days after the sprouting of the plants, with the average of 105.0 kg.ha-¹.day-¹; b) Extraction of macronutrients was the same in the two cultivars, with the exception of P; export was different only in the case of K and S; c) The extraction, in kg/ha and kilograms needed for the production of one metric ton of roots were respectively 113.3 and 6.21 for N, 11.0 and 0.62 for P, 78.6 and 4.24 for K, 62.0 and 3.37 for Ca, 18.5 and 1.00 for Mg and 8.3 and 0.46 for S; d) The export, in kg/ha and kg/ton of roots were respectively 39.1 and 2.12 for N, 3.9 and 0.22 for P, 32.5 and 1.71 for K, 12.1 and 0.66 for Ca. 6.7 and 0.36 for Mg and 1.7 and 0.09 for S.