We investigated French primary school teachers' assessment practice in mathematics. Using an online questionnaire on teachers' background, teaching, and grading practice, we were able to determine assessment profiles of 604 primary school teachers. As evidenced by the teachers' scores on the latent factors Assessment purposes, Assessment practices, and Differentiation, teachers with the profile of "Enthusiastic assessors" view assessment as more useful and use it more often to adapt their instruction than teachers with the profile of "Unenthusiastic assessors." This can be useful for practice and sheds more light on French teachers' assessment practices in mathematics. It is also interesting to compare the results of this survey with those from China and the Netherlands, as the differences reflect different assessment cultures and may shed light on some of the results of international large-scale assessments such as PISA.