A method for mounting a lead-through assembly in a wall, the lead-through assembly being adapted to provide a fluid communication through the wall in a direction of extension from a first side of the wall to a second side of the wall, the lead-through assembly comprising: - a lead-through device comprising a passage portion configured to extend through an opening in the wall to the second side of the wall and being adapted to provide the fluid communication, - a mounting bracket, the mounting bracket being adapted to receive the lead-through device such that the passage portion extends through an opening in the mounting bracket, the mounting bracket comprising at least one support section (14, 14') comprising an abutment surface (16, 16') configured to abut a first wall surface of the wall, the first wall surface being located on the first side of the wall, - a retainer being adapted to be attached to the passage portion of the lead-through device from the second side of the wall, the retainer comprising a contact surface adapted to press against a second wall surface located on the second side of the wall when the retainer is attached to the passage portion, the method comprising: - arranging the passage portion of the lead-through device through the opening in the wall, such that the abutment surface (16, 16') abuts the first wall surface, - attaching the lead-through device to the mounting bracket; - securing the at least one support section (14, 14') to the first wall surface by securing means extending in a direction from the second side of the wall and through the wall into the abutment surface, wherein substantially the complete available abutment surface can be utilized as an attachment zone for the securing means, the securing means being positioned arbitrarily within the area of the abutment surface, - fixing the lead-through assembly in the wall by attaching the retainer to the passage portion on the second side of the wall, such that the contact surface presses against the second wall surface of the second side of the wall, thereby creating a clamping force between the abutment surface (16, 16') of the at least one support section (14, 14') and the contact surface of the retainer. - a lead-through device comprising a passage portion configured to extend through an opening in the wall to the second side of the wall and being adapted to provide the fluid communication, - a mounting bracket, the mounting bracket being adapted to receive the lead-through device such that the passage portion extends through an opening in the mounting bracket, the mounting bracket comprising at least one support section (14, 14') comprising an abutment surface (16, 16') configured to abut a first wall surface of the wall, the first wall surface being located on the first side of the wall, - a retainer being adapted to be attached to the passage portion of the lead-through device from the second side of the wall, the retainer comprising a contact surface adapted to press against a second wall surface located on the second side of the wall when the retainer is attached to the passage portion, - arranging the passage portion of the lead-through device through the opening in the wall, such that the abutment surface (16, 16') abuts the first wall surface, - attaching the lead-through device to the mounting bracket; - securing the at least one support section (14, 14') to the first wall surface by securing means extending in a direction from the second side of the wall and through the wall into the abutment surface, wherein substantially the complete available abutment surface can be utilized as an attachment zone for the securing means, the securing means being positioned arbitrarily within the area of the abutment surface, - fixing the lead-through assembly in the wall by attaching the retainer to the passage portion on the second side of the wall, such that the contact surface presses against the second wall surface of the second side of the wall, thereby creating a clamping force between the abutment surface (16, 16') of the at least one support section (14, 14') and the contact surface of the retainer.