Much has been written about what the appropriate size of the prosthesis to be used in mammary surgery should be, when referring to breast augmentation as well as breast lift. There are numerous alternatives in terms of the shape of the prosthesis, the methods for placing them and the anatomy of the patient themselves. We could analyse the alternatives one by one and the reasons for each case but that would be enough to write a manual on plastic surgery. In this case, if you have any doubts, it is recommended you contact Dr. Javier Collado who will clarify the entire procedure. Broadly speaking, we can declare that we should not abuse the choice of large breast prosthesis as although in the beginning the patient may seem fine, in the long-term, the use of large breast prosthesis will lead to harmful effects in time. Among these effects, we highlight the accelerated ageing of the skin of the breasts as it is not the same having to support a 300 gr. prosthesis as it is having to support a 600 gr. one. On the other hand, it is known that the use of large breast prosthesis can cause an increase in the incidence of capsular contracture and this could cause another trip to the operating room for the removal of the implant and the capsule.