Strigolactones (SLs) have been defined as a new group of plant hormones or their derivatives that suppress lateral shoot branching. Recently, a new role for SLs was discovered, in the regulation of root development. Strigolactones were shown to alter root architecture and affect root-hair elongation. Here, I review the recent findings regarding the effects of SLs on root growth and development, and their association with changes in auxin flux. The networking between SLs and other plant hormones that regulate root development is also presented. Strigolactone regulation of plant development suggests that they are coordinators of shoot and root development and mediators of plant responses to environmental conditions.