The purpose of this study is to investigate students' mathematical creativity by analyzing their abilities to pose problems. The participants include 250 gifted and non-gifted students from both seventh and eighth grades representing four schools and four school districts in northwest Arkansas. The problem-posing test (PPT) is based on a divergent thinking technique consisting of five free-structured and semi-structured situations developed to assess the participants’ mathematical creativity. The content validity of the PPT is based on the responses of 15 mathematical experts and a subsequent pilot study of 60 students. In terms of reliability inter-rater and intra-rater reliability are conducted. This research follows Bonotto's (2013) method for assessing the quality of students' responses on the PPT, and the plausible problems are scored based on fluency, flexibility, and originality. The study rubric consists of 15 mathematical categories such as operations, algebra, sets, geometry, and probability with several subcategories under them. The total number of a student's plausible problem responses is defined as the student's fluency score, and the total number of subcategories involved in a student's plausible problems is defined as the student's flexibility score. Finally, the originality scores of the students' responses are based on their rareness. The results will help scholars better understand the connection between mathematical creativity and problem-posing abilities. Also, the work will illustrate some aspects of differences in mathematical creativity between gifted and non-gifted students.