  In this Thesis I studied the formation of the four giant planets of the Solar
System in the framework of the nucleated instability hypothesis. The model
considers that solids and gas accretion are coupled in an interactive fashion,
taking into account detailed constitutive physics for the envelope. The
accretion rate of the core corresponds to the oligarchic growth regime. I also
considered that accreted planetesimals follow a size distribution. One of the
main results of this Thesis is that I was able to compute the formation of
Jupiter, Saturn, Uranus and Neptune in less than 10 million years, which is
considered to be the protoplanetary disk mean lifetime.
