The present invention relates to electrical wiring components, and more particularly, to an electrical utility box having a mechanism for providing vertical adjustment after attachment to a wall stud, both before and after wall surface installation and during all phases of construction. A first preferred embodiment of the present invention includes an electrical utility box attached to a mounting bracket containing a slot placed longitudinally along the center of the bracket, thereby allowing the electrical utility box to slide along the length of the bracket. A second preferred embodiment includes an electrical utility box and a T-shaped mounting bracket permanently fixed to the electrical box, thereby allowing the combination to be used as a conventional electrical utility box assembly. In addition, an L-shaped optional adjustable mounting bracket to provides a vertical adjustment capability when combined with a T-shaped mounting bracket. A third preferred embodiment includes an electrical utility box attached to a mounting bracket by wrap-around tabs.