This is a descriptive study which attempts to answer how well 8th grade students define a rectangle. The subjects for this study were 93 of 8 th grade students. The students were administered a written open ended test on the definition of a rectangle which was adapted from Ahuja (1996). Responses of the students were coded by each researcher independently and common expressions were grouped. Then, new codes were created and the final codes were generated by the researchers. Findings of the study revealed that none of the students could provide sufficient and necessary conditions for their descriptions and definitions. Besides, it was seen that the majority of the students used the terminology incorrectly. While trying to define the rectangle, most of the students listed the properties of the rectangle and only a few students were able to construct a definition. Students mostly gave visual examples. From these findings, it can be concluded that students were unsuccessful in defining the rectangle and they were at Van Hiele Level 1.