Direct push technology (DPT, also known as direct drive, drive point, or push technology) refers to a growing family of tools used for performing subsurface investigations by driving, pushing, and/or vibrating small-diameter hollow steel rods into the ground. By attaching sampling tools to the end of the steel rods they can be used to collect soil, soil-gas, and groundwater samples. DPT rods can also be equipped with probes that provide continuous in-situ measurements of subsurface properties (e.g., geotechnical characteristics and contaminant distribution). Although environmental professionals recognize that DPT provide a cost-effective alternative to conventional approaches to subsurface sampling, some have been reluctant to use it for groundwater sampling because of uncertainty regarding the quality of samples that the technology can provide. This guidance is designed to encourage more widespread consideration of DPT by clarifying how DPT can be used to meet a variety of data quality requirements for a variety of site conditions. The primary audience for this guidance is EPA regional folks working on CERCLA, RCRA, and other related programs. It also may be useful for environmental professionals who oversee or undertake the collection of groundwater samples at contaminated sites and have a basic scientific understanding of groundwater sampling. Information is provided on the application and limitations of DPT for groundwater sampling activities. Although this document is not intended to provide substantial background information, Section 2 provides a general overview of DPT groundwater sampling and an extensive list of resources is cited within the text and listed in the reference section.