We have tried to understand the role of cellular tone (or internal tension mediatedby actin filaments) and interactions with the microenvironment on cellular stiffness. Forthis purpose, we compared the apparent elasticity modulus of a 30-element tensegritystructure with cytoskeleton stiffness measured in subconfluent and confluent adherent cellsby magnetocytometry, assessing the effect of changing cellular tone by treatment with cytochalasin D. Intracellular and extracellular mechanical interactions were analyzed on the basis of the non-dimensional relationships between the apparent elasticity modulus of the tensegrity structure normalized by Young's modulus of the elastic element versus: (i)element size, (ii) internal tension, and (iii) number of spatially fixed nodes, for smalldeformation conditions. Theoretical results and rigidity measurements in adherent cellsconsistently showed that higher cellular tone and stronger interdependencies with cellularenvironment tend to increase cytoskeleton stiffness. Visualization of the actin latticebefore and after depolymerization by cytochalasin D tended to confirm the geometrical andmechanical assumptions supported by analysis of the present model.