The aim of this study is to propose a categorization of concept drawings that permits the analysis of preservice primary teachers' conceptualization. Students were asked to draw a rectangle in the course of a mathematics lesson and a flower in that of science. The sample included 50 students from the primary education department at Uludag University, Bursa, Turkey. Their responses were analyzed using the same grid. Two main categories were distinguished: the drawing of a concept's structure (conceptual, iconic, redundant/missing drawing) and labeling/coding of the concept's parts (comprehensive, partial, incorrect labeling). The first finding shows that students who produced a response categorized as conceptual and iconic drawings were identified as in the comprehensive labeling category. Thus, there may be a relationship between conceptual and iconic drawings and conceptual comprehension. Another finding concerns the similarities in the categorization of responses for both maths and science questions. Students who made iconic and conceptual drawings were able to label more correctly than students who drew a redundant/missing drawing. In addition, it can also be said that for the biology drawing the whole flower was observed whereas in geometry an abstract subject which is not generally observed was made physical by the drawing. (C) 2010 Elsevier Ltd. All rights reserved.