A laundry washing machine (1) has a casing (2) supporting a washing tub (3) external to a washing drum (4) suitable to receive the laundry to be washed, and a detergent supply system (5; 35; 55; 65; 105) comprising a mixing chamber (6; 56; 86; 106) suitable to receive detergent (D) and water (W). A mixing device (20; 40; 100) suitable to mix the detergent (D) and the water (W) in the mixing chamber (6; 56; 86; 106) to form a washing solution (S) is provided. The mixing chamber (6; 56; 86; 106) and the mixing device (20; 40; 100) are disposed inside the casing (2) and the mixing chamber (6; 56; 86; 106) comprises an inlet (7; 57; 87; 107) accessible from outside the casing (2) for the insertion of the detergent (D) and an outlet (14; 94) for delivering the washing solution (S) in the washing tub (3).