Agricultural products are affected by static and dynamic forces at different stages of harvesting, handling and processing. In most cases, the damages are inflicted upon raw products. In the present study the mechanical properties of tomato fruits were found out for two cultivars (Super Bta and Petoerly Ch), during 4 periods of time (1, 5, 10 and 15 days past harvest), and at two levels of fruit sizes (small and medium). Statistical analysis was performed in the form of a split-plot arrangement in time with a completely randomized design of 10 replications. The effect of time past harvest was significant on the exerted force and deformation at bioyield points. Rate of deformation and rate of force at biologic yield points were found out to be greater for petoerly Ch than for super Bta variety. Also, the effect of variety was significant on deformation at rupture point. Tomatoes with of the small size were found to be tougher than the medium ones. Smaller size fruits are tougher and need less force to rupture. Also, significant differences were observed between different size fruits for the following parameters: maximum force, maximum deformation, deformation at rupture point and force at bioyield point. At one day past harvest petoerly variety was found to be of more strength, in ui-naxial loading, than super Bta, as compared with other points of time.