Abstract : Horizontal directional drilling (HDD) is a versatile form of utility construction and has seen enormous growth in the last decade as it offers a clear alternative to conventional methods. Drilling is conducted in both the vertical and horizontal direction and can be steered within limits, dependent upon subsurface conditions. HDD can install utilities from 1" to 48" in diameter and up to 6000 feet in length. The major utilities (gas, electric, telecommunications and water/sewer) can be installed with this technology. The construction process (pilot hole, reaming and pullback) along with the major components (drill rig, drill pipe, slurry, slurry recycling, survey equipment, drill bits, reamers and pipeline materials) will be discussed. The advantages of cost reduction, and environmental, social and time benefits will be examined in the context of numerous case studies. The challenges of proper soils information, subsurface conditions, training and knowledge, drilling fluids and binding of the drill pipe and reamer/bit will be discussed. Through constant innovation, HDD should remain state of the art for some time, and should be a consideration for the construction of any new utility within the size parameters.