Testing and teaching are completely interrelated in education process; using various kinds of tests teachers are able to anticipate about the strong and weak points of learning in students, their progress and their accomplishment. The influence a test on teaching and learning is commonly referred to as washback. Testing washback is a twisted concept that becomes even more complex under a various interpretations of the washback phenomenon on teaching and learning. This study aimed to describe washback behaviors of students, in the low stakes testing in an ESP environment in two-fold. First, the study investigated the effects of different formative tests on Iranian medical students' English reading comprehension achievement. Secondly, the study explores the effects of washback on the students' attitudes toward English reading comprehension. The pre- and post-tests and one questionnaire were used to collect the data from Iranian medical students. Data were analyzed by paired t-test, t-test, and Mann-Whitney U test.

Inclusion Criteria:

• nursing students
• study at mums

Exclusion Criteria:

• other disciplines
• study at other universities