Modular closet system, comprising: - wall elements for forming side and partition walls of a closet arrangement; - rear wall elements for forming rear walls of a closet arrangement; - a set of connection profiles for the connection of the wall elements and the rear wall elements with each other, said set of connection profiles include the following profiles: - wall coupling profiles (10, 20), each of which comprise first holding elements (11, 21) for holding the wall elements and first coupling means (12, 22) for the coupling of other connection profiles of the set; - rear wall functionalizing profiles, each of which comprise second holding means for holding the rear wall elements, second coupling means which are complementary to the first coupling means (12, 22) for coupling of the rear wall functionalizing profiles to the wall coupling profiles (10, 20), and first suspension means provided for receiving complementary second suspension means; - rear wall coupling profiles, different from the rear wall functionalizing profiles, which also comprise the second holding means means for holding the rear wall elements and the second coupling means which are complementary to the first coupling means (12, 22) of the wall coupling profiles (10, 20), characterized in that rear wall coupling profiles are diffent from said rear wall functionalizing profiles in that the second coupling means are provided on both sides of the rear wall coupling profiles such that a closet arrangement can be formed with wall elements on both sides of the rear wall elements, and that the closet system further comprises functional elements exhibiting the second suspension means, which are provided to be mounted to the rear walls of the closet arrangement through the rear wall functionalizing profiles and which are provided for giving a functionality to the rear wall of the closet arrangement in the interior of a house. - wall elements for forming side and partition walls of a closet arrangement; - rear wall elements for forming rear walls of a closet arrangement; - a set of connection profiles for the connection of the wall elements and the rear wall elements with each other, said set of connection profiles include the following profiles: - wall coupling profiles (10, 20), each of which comprise first holding elements (11, 21) for holding the wall elements and first coupling means (12, 22) for the coupling of other connection profiles of the set; - rear wall functionalizing profiles, each of which comprise second holding means for holding the rear wall elements, second coupling means which are complementary to the first coupling means (12, 22) for coupling of the rear wall functionalizing profiles to the wall coupling profiles (10, 20), and first suspension means provided for receiving complementary second suspension means; - rear wall coupling profiles, different from the rear wall functionalizing profiles, which also comprise the second holding means means for holding the rear wall elements and the second coupling means which are complementary to the first coupling means (12, 22) of the wall coupling profiles (10, 20), characterized in that rear wall coupling profiles are diffent from said rear wall functionalizing profiles in that the second coupling means are provided on both sides of the rear wall coupling profiles such that a closet arrangement can be formed with wall elements on both sides of the rear wall elements, and that