Machine for disposing of solid plastic sacks containing liquid, e.g. sacks with bladder catheters or other flexible tubes used in hospital departments, comprising a first hopper suitable for receiving said sacks by gravity force, a shredder placed inside said first hopper comprising at least one shredding unit having a first shaft and a second shaft driven by said first shaft, said first and second shafts being provided with a plurality of disks (7,12), each of said disks being provided with sharp protuberances set to break said sacks and allowing to spill out the liquid contained therein, and by at least one comb device having a plurality of fixed teeth cooperating with said sharp protuberances of said disks (7,12), of said first and/or said second driven shaft, said machine comprising at least one solid/liquid separator apparatus for separating solid parts from liquid parts of said plastic sacks coming from said shredder, said device comprising a container having a bottom wall inclined towards a liquid outlet, the liquid outlet comprising a plurality of holes, and a plurality of rotating paddles having a known angular speed and positioned in the container in order to move the solid waste towards an outlet opening, said machine comprising a further solid/liquid separator apparatus for at least part of the residues of said solid and liquid parts leaving from said at least one separator apparatus, said machine being characterized in that said further separator apparatus comprises at least one basket inside which a radial impeller is contained, said basket being arranged inside a tank, said tank being provided with at least one opening for discharge of said liquid parts and at least one opening for discharge by gravity force the said solid parts resulting from said separation of said solid parts from said liquid parts. said first and second shafts being provided with a plurality of disks (7,12), each of said disks being provided with sharp protuberances set to break said sacks and allowing to spill out the liquid contained therein, and by at least one comb device having a plurality of fixed teeth cooperating with said sharp protuberances of said disks (7,12), of said first and/or said second driven shaft, said machine comprising at least one solid/liquid separator apparatus for separating solid parts from liquid parts of said plastic sacks coming from said shredder, said device comprising a container having a bottom wall inclined towards a liquid outlet, the liquid outlet comprising a plurality of holes, and a plurality of rotating paddles having a known angular speed and positioned in the container in order to move the solid waste towards an outlet opening, said machine comprising a further solid/liquid separator apparatus for at least part of the residues of said solid and liquid parts leaving from said at least one separator apparatus, said machine being characterized in that said further separator apparatus comprises at least one basket inside which a radial impeller is contained, said basket being arranged inside a tank, said tank being provided with at least one opening for discharge of said liquid parts and at least one opening for discharge by gravity force the said solid parts resulting from said separation of said solid parts from said liquid parts.