Peeling of cassava tubers, for both domestic and industrial purposes, is still being carried out manually. To provide data and a scientific basis for the development of a mechanical cassava peeler, some physical and mechanical properties of cassava roots were measured. These properties include the percentage by weight of peel in the roots (p), the root surface taper angle (a,), the root peel thickness (t), the root diameter (d), and the root peel penetration force per unit length of knife-edge (F). The results showed that p ranged from 10.6% to 21.5%; alpha(r) ranged from 0.0degrees to 22degrees; t ranged from 1.20 to 4.15 mm; d ranged from 18.8 to 88.5 mm; and F ranged from 0.54 to 2.30 N/mm. A linear relationship was established between the peel thickness and root (slice) diameter, as well as between the peel penetration force and root (slice) diameter. (C) 2003 Elsevier Science Ltd. All rights reserved.