A hose reel for a flexible hose, for example a flat garden hose, which can be supplied by a water-supply system, the hose reel comprising: - at least one fitting having a first male or female coupling for the removable connection with the water-supply system and a second male or female coupling for the removable connection with the flexible hose; - a rotatable element for rotatable winding/unwinding around a first axis to allow the winding/unwinding of at least one portion of the flexible hose, said rotatable element comprising at least one first and one second support element (101, 102) integrally joined rotatable around said first axis which include a respective first and second contact surface (23', 23") for the at least one wound portion of flexible hose; wherein at least one of said first and one second support element (101, 102) is movable along a radial direction with respect to said first axis so that said at least one first and one second support element (101, 102) move between a mutually distal and a mutually proximal position, wherein both in said distal position and in said proximal position said first and second contact surfaces (23', 23") remain mutually spaced to prevent said at least one portion of hose is compressed between them; wherein said rotatable element further includes a compartment interposed between said at least one first and one second support element (101, 102), said compartment being accessible by a user both when the same are in mutually proximal position and when in mutually distal position, said at least one fitting and said rotatable element being mutually connected so that said second male or female coupling is inside said compartment to allow the user to removably connect it with the flexible hose; wherein said rotatable element comprises a spindle (10") interposed between said at least one first and one second support element (101, 102) rotatably integrally joined with the latter around said first axis, said spindle (10") internally comprising said compartment; characterized in that it further comprises a pair of half-shells (49', 49") coupled with said rotatable element to guide it during the rotation, said half-shells (49', 49") being mutually joined to each other to surround said rotatable element, said half-shells (49', 49") including an opening so as to allow the user to access said compartment. - at least one fitting having a first male or female coupling for the removable connection with the water-supply system and a second male or female coupling for the removable connection with the flexible hose; - a rotatable element for rotatable winding/unwinding around a first axis to allow the winding/unwinding of at least one portion of the flexible hose, said rotatable element comprising at least one first and one second support element (101, 102) integrally joined rotatable around said first axis which include a respective first and second contact surface (23', 23") for the at least one wound portion of flexible hose; wherein at least one of said first and one second support element (101, 102) is movable along a radial direction with respect to said first axis so that said at least one first and one second support element (101, 102) move between a mutually distal and a mutually proximal position, wherein both in said distal position and in said proximal position said first and second contact surfaces (23', 23") remain mutually spaced to prevent said at least one portion of hose is compressed between them; wherein said rotatable element further includes a compartment interposed between said at least one first and one second support element (101, 102), said compartment being accessible by a user both when the same are in mutually proximal position and when in mutually distal position, said at least one fitting and said rotatable element being mutually connected so that said second male or female coupling is inside said compartment to allow the user to removably connect it with the flexible hose; wherein said rotatable element comprises a spindle (10") interposed between said at least one first and one second support element (101, 102) rotatably integrally joined with the latter around said first axis, said spindle (10") internally comprising said compartment; characterized in that it further comprises a pair of half-shells (49', 49") coupled with said rotatable element to guide it during the rotation, said half-shells (49', 49") being mutually joined to each other to surround said rotatable element, said half-shells (49', 49") including an opening so as to allow the user to access said compartment.