The present study aimed at identifying the challenges of “descriptive evaluation” program launched by the Ministry of Education in Iran in 2004, nationwide. The research was designed through employing qualitative approach and phenomenography to better understand the challenges which elementary teachers had with evaluation of “mathematics” as one of the subject matters. The participants of the study were 24 elementary teachers who voluntarily participated in this study.  The data were collected through semi- structured interviews, a focus group and researchers’ field notes and their interactive discussions about interviews and focus group. Four main categories of challenges were identified: “policy- making”, “executive- education”, “conceptual” and “social- cultural”. It is concluded that a clearer picture of challenges that elementary teachers encounter with this program while teaching mathematics needs to be presented. It is necessary for policy- makers and planners to find more rational solutions for these challenges.