Described is a method for checking syringe bodies of the type comprising a hollow body, a seal for closing the hollow body and a dose of a liquid product enclosed by the hollow body and by the seal, the method comprising the steps of applying a pneumatic negative pressure to the syringe body and moving a stop body towards the syringe body in such a way that, during at least a part of the step of applying the pneumatic negative pressure, the stop body obstructs withdrawal of the seal towards a rear end of the syringe body opposite the liquid.