The galactomannan from the seed of Cassia javanica L. was extracted in 26% yield and submitted to viscosity measurements. The intrinsic viscosity [eta] = 11.3 dl/g was determined at 25 degrees C and used to calculate the viscosity average molecular weight, (M) over bar(v) = 1.5 x 10(6). Variation of the specific viscosity at zero shear rate as a function of the coil overlap parameter revealed two critical concentrations, C* = 0.54 and C** = 2.6 g/l, more frequently observed for rigid polysaccharides.