The aim of this study is twofold: to determine which knowledge type (procedural or conceptual) is predominant in basic mathematics topics among preservice primary mathematics teachers and the relation between these knowledge types. The study group consisted of 97 freshmen studying at Primary Mathematics Teaching Department. Case study method was used within the scope of descriptive approach. Participants were administered the Conceptual-Procedural Knowledge Test (CPKT), developed by the researchers, which consisted of questions that measured procedural and conceptual knowledge. Participant answers were analysed by an answer key and a characterization scale, and their levels were determined according to level ranges. Then, the frequency and percentage of the data were calculated and tabularized, and charts were used to make a two-way comparison of the relationship between procedural and conceptual knowledge. The study revealed that preservice teachers' procedural knowledge was concentrated at levels 2 and 3 whereas their conceptual knowledge at levels 1 and 2. Another result of the study is that while conceptual learning may support procedural learning the contrary is not necessarily true.