Automatic nozzle for firefighting low-pressure water mist systems comprising a nozzle body and shutter means, said nozzle body comprising a plurality of axial-symmetric components defining an inlet opening and a plurality of inner cavities, which are fluid-dynamic connected each other by means of one or more openings, being said components located in a way to share the same symmetry axis and configured to generate: - a radial spray through a circumferential opening, which extends all over the circumference of a second component, said circumferential opening being formed between a base of a cylindrical wall of the second component and an upper surface of a hollow body of a third component, and - two or more full cone sprays (10") by means of the fluid passage through cylindrical openings on a circular and axial-symmetric body of a fifth component, configured to define a turbulent motion of the fluid in at least two correspondent cylindrical cavities of a fourth component, said two or more full cone sprays (10") out coming through at least two orifices fed by the at least two correspondent cylindrical cavities, said automatic nozzle wherein: - the axis of each of said cylindrical openings of the fifth component is inclined of a first angle (β) ranging between 10° and 80° with respect to an upper surface of the circular and axial-symmetric body, - the axis of each of said cylindrical openings has a second inclination of a second angle (γ) ranging between 30° e 90° and laying on a plane, which is tangent to the upper surface of the circular and axial-symmetric body and contains the intersection points (R', R) between the upper surface and the axis of said cylindrical openings converging towards a same orifice of the two or more orifices, said second angle (γ) being comprised between the projection of the axis of said cylindrical openings on the plane and a straight line (r), passing through the intersection points (R', R"). - a radial spray through a circumferential opening, which extends all over the circumference of a second component, said circumferential opening being formed between a base of a cylindrical wall of the second component and an upper surface of a hollow body of a third component, and - two or more full cone sprays (10") by means of the fluid passage through cylindrical openings on a circular and axial-symmetric body of a fifth component, configured to define a turbulent motion of the fluid in at least two correspondent cylindrical cavities of a fourth component, said two or more full cone sprays (10") out coming through at least two orifices fed by the at least two correspondent cylindrical cavities, - the axis of each of said cylindrical openings of the fifth component is inclined of a first angle (β) ranging between 10° and 80° with respect to an upper surface of the circular and axial-symmetric body, - the axis of each of said cylindrical openings has a second inclination of a second angle (γ) ranging between 30° e 90° and laying on a plane, which is tangent to the upper surface of the circular and axial-symmetric body and contains the intersection points (R', R) between the upper surface and the axis of said cylindrical openings converging towards a same orifice of the two or more orifices, said second angle (γ) being comprised between the projection of the axis of said cylindrical openings on the plane and a straight line (r), passing through the intersection points (R', R").