It is generally considered that diagram use aids efficacy of math word problem solving. While understanding diagrams is considered important in both New Zealand and Japanese secondary schools, there is an additional emphasis in New Zealand schools for students to appreciate their use as tools for problem solving and communication. This study examined whether there are actual differences in the amount and quality of diagrams that students in New Zealand and Japan use when given math word problems to solve. The participants were 614 secondary school students from New Zealand and Japan, aged 13 to 15 years old, who were given one- and two-object math word problems (involving length or non-length components) to solve. The findings were that while the New Zealand students evidenced greater diagram use and provided more correct answers, they produced significantly more high quality diagrams only for the easiest problems given (the one-object problems with length story context). One implication of the findings is that greater emphasis needs to be placed on, and/or more effective strategies need to be used in, developing New Zealand students' skills in the use of diagrams for solving more complex types of problems. (Contains 5 tables.) [This paper has been published as: Manalo, E., & Uesaka, Y. (2006). Quantity and quality of diagrams used in math word problem solving: A comparison between New Zealand and Japanese students. "Refereed papers of the NZARE (New Zealand Association for Research in Education) National Conference 2006" (CD-ROM; ISSN 1176-4902). Wellington, New Zealand: NZARE.]