An aquarium filter including a casing (2) with two respectively internal and external parts (2b,2c), which can be arranged straddling an aquarium wall, a filtration chamber (4) made in one of said parts and arranged with a seat to accommodate a cartridge positioned so as to intercept a route of the water to be filtered, a pump (28) and a delivery tube extending between said pump and said filtration chamber, characterized in that said cartridge seat (7) is made in the external part and said pump is housed in the internal part and is connected to a delivery tube integrated into said casing.
