The invention relates to a method for making an internal medical device to be implanted in a patient's body, which method particularly includes the following steps: (a) generating a digital data set representative of the three-dimensional shape of the body part in which said internal medical device is to be implanted; (b) fast-prototyping a mould cavity of which the shape matches the shape defined by the digital data set generated in step (a); (c) casting a mould around the mould cavity using a precursor of a refractory material; (d) treating the mould to give a refractory material; (e) removing the cavity from the mould; (f) casting a molten metal or alloy in the mould according to step (e) and removing said mould to give said internal medical device.