The Cu2+ hydration shell structure has been studied by a combined ab initio quantum mechanical/molecular mechanical (QM/MM) Monte Carlo simulation, in which the ion and its first hydration sphere are treated at the Born-Oppenheimer ab initio quantum mechanical level, while classical pair and three-body potentials are employed for the remaining system. Whereas traditional simulations based on MM potentials are not able to predict higher-body effects such as the Jahn-Teller (JT) distorted octahedral structure of the first hydration shell of Cu2+, the combined QM/MM approach reproduces correctly this experimentally confirmed property and delivers more accurate hydration energy values as well.