A combined study of the high pressure crystallography and high pressure magnetism of the complex [Mn-3(Hcht)(2)(bpy)(4)](ClO4)(3)center dot Et2O center dot 2MeCN (1 center dot Et2O center dot 2MeCN) (H(3)cht is cis, cis-1,3,5-cyclohexanetriol) is presented in an attempt to observe and correlate pressure induced changes in its structural and physical properties. At 0.16 GPa the complex 1 center dot Et2O center dot MeCN loses all associated solvent in the crystal lattice, becoming 1. At higher pressures structural distortions occur changing the distances between the metal centres and the bridging oxygen atoms making the magnetic exchange between the manganese ions weaker. No significant variations are observed in the Jahn-Teller axis of the only Mn-III present in the structure. High pressure dc chi T-M plots display a gradual decrease in both the low temperature value and slope. Simulations show a decrease in J with increasing pressure although the ground state is preserved. Magnetisation data do not show any change in vertical bar D vertical bar.