Device for signalling direction for cyclists, comprising a wearable support to be firmly set onto the head of a user, on which said support is worn, in use, said support having a flattened profile and shaping side portions opposite and symmetrical with respect to a median axis, said side portions having the shape of a "V" directed outwardly; an electric power supply device, housed in said wearable support; a plurality of position light sources, housed on said wearable support, configured to selectively signal the state of charge of said electric power supply device or the position of the user wherein the number of turned on position light sources being indicative of a predetermined percentage of charge of said power supply device; at least a first direction light source and a second direction light source, each indicating a respective direction of rotation of said wearable support, said first and second direction light sources being shaped so as to respectively shape, at each said end portion of said support, the shape of a "V" directed outwardly; at least one sensor element associated with said wearable support, to measure at least one value of the acceleration and/or one value of the angular speed assumed by said wearable support when it is worn on said head of a user; a control unit electrically connected to said first direction light source and to said second direction light source, said at least one sensor element being configured to send said measured values to said control unit; said control unit being configured to process an angular measurement of the rotation carried out by said wearable support and to control, upon exceeding predetermined values of said angular rotation measurement, the selective turning on and/or turning off of said first direction light source and of said second direction light source, so as to signal a direction of said rotation identified by said angular measurement; said first and second light source, said at least one sensor element and said control unit being housed on said wearable support. a wearable support to be firmly set onto the head of a user, on which said support is worn, in use, said support having a flattened profile and shaping side portions opposite and symmetrical with respect to a median axis, said side portions having the shape of a "V" directed outwardly; an electric power supply device, housed in said wearable support; a plurality of position light sources, housed on said wearable support, configured to selectively signal the state of charge of said electric power supply device or the position of the user wherein the number of turned on position light sources being indicative of a predetermined percentage of charge of said power supply device; at least a first direction light source and a second direction light source, each indicating a respective direction of rotation of said wearable support, said first and second direction light sources being shaped so as to respectively shape, at each said end portion of said support, the shape of a "V" directed outwardly; at least one sensor element associated with said wearable support, to measure at least one value of the acceleration and/or one value of the angular speed assumed by said wearable support when it is worn on said head of a user; a control unit electrically connected to said first direction light source and to said second direction light source, said at least one sensor element being configured to send said measured values to said control unit; said control unit being configured to process an angular measurement of the rotation carried out by said wearable support and to control, upon exceeding predetermined values of said angular rotation measurement, the selective turning on and/or turning off of said first direction light source and of said second direction light source, so as to signal a direction of said rotation identified by said angular measurement; said first and second light source, said at least one sensor element and said control unit being housed on said wearable support.