Quantification of structure is a desirable goal if the mechanical properties of cellular solids such as bread crumb are to be predicted. This study determined the influence of cellular structure on the mechanical properties of bread crumb. Variation in structural and mechanical properties was obtained by varying flour type, water content and dough processing conditions. Cellular structure was characterised by crumb relative density and various structural parameters determined by digital image analysis. Mechanical properties were determined by tensile testing. Young's modulus and failure stress were successfully fitted (0.55=< R 2 =<0.94) to the relative density power law model proposed by Gibson and Ashby. However, the fitting exponents between mechanical properties and relative density were lower than their theoretical values. By incorporating effects of strain hardening in the crumb solids, and of missing cell walls (due to gas cell coalescence), with the theoretical effect of relative density, estimates could be obtained for strain hardening exponents (p) of doughs of different baking strength (1.5< p<6.5). These values concurred with p values from other researchers biaxial extension experiments. Estimates of Young's modulus and failure stress of the crumb solids ranged from 280-440 kN m - 2 , and from 14-22 kN m - 2 , respectively, when the revised Gibson and Ashby model was used.