Cotton production soils of the southeastern Coastal Plain are sandy and often overlie a subsurface hardpan that restricts the root zone. This can be a serious problem in years with insufficient rainfall. Mechanical disruption of the hardpan, most frequently by subsoiling, is widely recommended to increase the root zone. The process is expensive and the effects are temporary. Cotton cultivars with roots able to penetrate a subsoil hardpan would have the potential to decrease the need for subsoiling and significantly reduce production costs. Our objective is to identify germplasm with greater ability to penetrate compacted soil. Twenty-four cotton genotypes of diverse ancestry including 14 cultivars and 10 Pee Dee germplasm lines were evaluated in field plots without irrigation over a naturally-compacted subsoil near Florence, SC. At the end of the season, plants were dug to examine roots and then rated on a 1-5 scale based on magnitude of the taproot penetration of the hardpan. Among the 14 cultivars, PD-1 performed best (3.46 rating) while CB 407 (2.21 rating) had the poorest penetration of the hardpan. Of the 10 germplasm lines, PD 5529 performed best (3.35 rating) while PD 695 (1.79 rating) was least able to penetrate the subsoil hardpan. These data clearly demonstrate genotypic variation for rooting ability through a subsoil hardpan. We conclude that ability to penetrate a subsoil hardpan should be part of the evaluation process before using germplasm lines for development of new cultivars for use in geographic regions that have subsoil hardpans.