This five-month study examined the writing behavior of 8 fifth-grade students as they composed original mathematics story problems. An analysis of observations indicated that students developed three strategies for writing story problems. First, students usually engaged in question-directed behavior during problem writing. After they identified the general problem topic, students generated the culminating question that they then used to guide composition of the problem text. At other times, students used a free association strategy: They generated their information by making associations with the general topic, wrote the problem text, and then identified the culminating question. Finally, all students developed techniques to make their problems more difficult. Overall, the analysis of students, problem writing behavior contributes to an understanding of the story-problem writing process. The study further suggests that students may be able to collaborate effectively with teachers in writing the mathematics curriculum.