In order for the peanut shell waste to have an economic value, it should be processed mechanically. Among others, for instance, utilization of peanut shells as a fuel source or insulation material requires them to be compressed. Thus, for a rational design of such machinery, there is a need to know the behavior of peanut shells under compressive static loads and the associated physico mechanical properties. To those ends, experiments were carried out, using the local Turkish cultivars Osmaniye, Silifke, Anamur and Antalya. Mathematical models for force-deformation, pressure-strain and pressure-density relationships were obtained from the test data. Linear and non-linear behaviors in the first, third and second regions of the test domain were determined, respectively. Limiting values of pressure, density, stiffness, bulk moduli, compression ratio and compression energy per volume were estimated. For the cultivars tested, stiffness values varied between 19.7 and 52.6 N mm^-1 in the first region, between 12402.0 and 5111.2 N mm^-1 in the third region. Bulk moduli ranged from 0.184 to 0.471 N mm^-2 in the first region, and from 46.886 to 110.182 N mm^-2 in the third region. Compression energy per volume and compression ratio were found between 0.1976 and 0.2916 N mm.mm^-3, and between 4.0 and 4.4, respectively.