A safety device against fluid leaks for household appliances, designed for connection between a source of the fluid and a household appliance, comprising: - a first connection body and a second connection body, which define a first duct and a second duct for the fluid, respectively; - a valve arrangement including a valve member, mounted on the first connection body and designed to assume a position of opening and a position of closing of the first duct, and means for accumulating mechanical energy, to force the valve member towards the respective position of closing of the first duct; - control means, for withholding the valve member in the respective position of opening, countering the action of the means for accumulating mechanical energy, the control means being operable for assuming a respective position of release of the valve member; - a flexible inner hose and a flexible outer hose which are impermeable to the fluid, wherein the inner hose connects in fluid communication the first duct and the second duct and extends longitudinally at least in part within the outer hose, such that between at least part of the two hoses (16, 17) a gap having a proximal end and a distal end is defined, the gap being substantially closed at said ends for withholding inside it possible leaking fluid, wherein: - the first connection body comprises a control chamber with a movable element, - the control means comprise a control or retention member associated to the movable element, wherein the gap is in fluid communication with the control chamber to form therewith a substantially closed volume, or anyway such that an internal fluid leak towards the gap or the aforesaid substantially closed volume causes a movement of the movable element, and thereby an actuation or displacement of the control member to the corresponding position of release of the valve member, in which the valve member is free to assume the respective position of closing of the first duct, characterized in that - the movable element consists of an elastically deformable element which delimits at least in part the control chamber and which is capable of bending between an inoperative position and an operative position; - the control member is coupled to the elastically deformable element such that a bending of the elastically deformable element from the inoperative position into the operative position causes a displacement of the control member towards the respective position of release. - a first connection body and a second connection body, which define a first duct and a second duct for the fluid, respectively; - a valve arrangement including a valve member, mounted on the first connection body and designed to assume a position of opening and a position of closing of the first duct, and means for accumulating mechanical energy, to force the valve member towards the respective position of closing of the first duct; - control means, for withholding the valve member in the respective position of opening, countering the action of the means for accumulating mechanical energy, the control means being operable for assuming a respective position of release of the valve member; - a flexible inner hose and a flexible outer hose which are impermeable to the fluid, - the first connection body comprises a control chamber with a movable element, - the control means comprise a control or retention member associated to the movable element, - the movable element consists of an elastically deformable element which delimits at least in part the control chamber and which is capable of bending between an inoperative position and an operative position; - the control member is coupled to the elastically deformable element such that a bending of the elastically deformable element from the inoperative position into the operative position causes a displacement of the control member towards the respective position of release.