Investigations of compact bone tissue mechanical behaviour under cyclic loading provide important information for oral implantology and orthodontics. Fatigue and repeated load of mandibular bone play a major role in the fixation and stability of prosthetic implants and their stems for fixation into bone cavities. Cyclic loading may compromise the initial fixation of the implant, allowing for and the establishment of a new loading environment. The objective of this investigation was to study the fatigue behaviour of pig jaw compact bone material specimens subjected to compression tests. Samples for experiments were prepared from three 2 year old pig lower jaws. Specimens were tested under cyclic load with peak load levels that were 60%, 70%, 80%, and 90% of the compressive yield strength with a frequency of 2 Hz. For all specimens the density was measured using hydrostatic weighting method. Twenty six specimens were loaded to fracture to determine the ultimate compressive stresses and to find a correlation and regression between density and yield strength. The level of loading for 30 specimens was calculated using regression equation obtained in the previous step. Fatigue tests of pig jaw cortical bone in compression were conducted and results were summarized as peak stress versus cycles. Experimental data were approximated using reversed power function. Compressive cyclic loading and time to failure were predicted, according to the cumulative damage model, by the accumulation of cycle-dependent damage only. In the investigation it was found that fatigue properties depended from the location of specimens in jaw bone and that there was negative correlation between cycles to failure for fatigue specimens of the pig mandible compact bone tissue and bone density for all cyclic loading levels. The obtained results may help to understand the behavior of jaw compact bone tissue under cyclical loads and should be taken into account in designing treatment programs and in improvement of mechanical parameters of endosseous implants.