The mechanisms of association between neutral xyloglucan chains extracted from tamarind seeds are explored. Mesoscale structures involving a few chains are evidenced and monitored by static light scattering and low-shear viscosity experiments as a function of the xyloglucan concentration, obtained from increasing the dilution of an initial dispersion. The mechanism of association is addressed by means of multiangle dynamic light scattering. The associations exist whether the chains are in the dilute regime or in the semi-dilute regime and are characteristic of weak interactions. Their progressive loosening by dilution is evidenced and their level depends only on the xyloglucan concentration. The associations are due to a mechanism inherent to the nature of the chains