Proposed invention refers to a method for anonymously associating health monitoring device measurements to a user ID. The invention comprises the steps of: registering in a server a user associated with an ID and a first set of metadata; registering a health monitoring device associated to a second ID and a second set of metadata; then, sending through a first communication channel the ID associated to the user and the first set of metadata to the server by a communication device; taking a measurement of the user by the health monitoring device and sending through a second communication channel said measurement associated to the second ID and the second set of metadata to the server; comparing the metadata stored in the server; and finally associating the first ID with the measurements taken by the health monitoring device corresponding to the second set of metadata, being based the association on the results of the previous comparison.