In this work, the effects of storage period on nine mechanical properties and moisture content of stored yam (Dioscorea spp) tubers were investigated. The mechanical properties of whole intact yam tubers of three yam (Dioscorea spp) cultivars in various treatments including: four levels of storage time at 75 days interval spanning 225 days, and four levels of loading positions namely at the head, middle, tail and vertical, were presented in this study. Mechanical compression tests were performed on three different cultivars namely: Ogoja, Gbangu and Agbo-yian. The results of the study showed that the force at bio-yield point, force at peak point, force at breaking point, and energy at bio-yield point during compression test in general is significantly higher in the middle of the tuber than other locations. The value for bio-yield force range from 1059 N for Agbo-yian to 4,500 N for Gbangu. So for safe stacking of Dioscorea alata in containers and stacks 1059 N is safe while for Dioscorea rotundata 4,500 N would be adequate. Energy follows the same pattern as forces. Results obtained from this study will be helpful in the design and fabrication of yam tubers harvesting and handling machines.