Recent work stimulated by Piaget & Inhelder's (1956) account of spatial development indicates that children as young as 4 years of age are capable of using Euclidian coordinate reference systems. However, the exact basis for this early ability is yet to be established; specifically, although we know a good deal about the conditions under which young children are capable of interpreting spatial coordinate cues to locate an object, less is known about their ability to construct spatial coordinate cues to indicate the location of an object. The current study investigates the ability of children aged 4-5 years to locate a hidden object by coordinating information provided by markers in orthogonal dimensions (interpretation task) and to correctly position orthogonally orientated markers to indicate the location of a hidden object (construction task). Performance was superior on the construction task, with a clear majority of children performing significantly above chance. Additionally, performance on the interpretation task improved following the construction task. The results serve to extend rather than falsify the Piagetian account, by indicating that in simple tasks 4- to 5-year-olds are capable of both interpreting and constructing coordinate dimensions. It is possible that the child's engagement in the activity of construction may have made the task principles more transparent, enhancing performance in the process. The findings have consequences as to the age and manner in which children are introduced to tasks, such as map work, which involve the use of dimensional coordination.