Subsurface drip irrigation (SDI) has been suggested as a high efficiency alternative to other irrigation methods largely because it eliminates surface evaporative losses typical of other methods. However, limited work has been done on SDI effects on season-long root distribution through the soil profile. Root distribution under SDI is important since roots constrain the responsiveness of the crop to irrigation events, the crop's ability to extract existing water from the soil profile, and precipitation use efficiency. We investigated root distribution of cotton to SDI at three different irrigation levels and under dryland conditions. Cotton was planted in beds 1 meter (40 inches) center to center with drip irrigation tubes installed in furrows on 2 meter (80 inch) centers. Minirhizotron tubes were installed at 45 degrees to a depth of one meter parallel to rows within the furrows and the rows. Images were collected throughout the growing season and analyzed for occupancy and root length density.