The objectives of this mixed-method study are to study washback effect of task-based language ‎assessment on developing reading skill and also students` attitude towards TBLA. ‎108 EFL learners ‎‎participated in the study were randomly chosen and were allocated into two classes of 54. The two ‎groups took a reading class which carried out 90 minutes per week and continued for 3 months. By ‎administering the PET, the homogeneity of two groups was approved. Both groups received similar ‎instruction over 24 sessions, but only participants in experimental class took the researcher-‎designed task-based reading quizzes each four sessions. Next, both groups were given a reading ‎post-test after the treatment, Results showed that TBLA has a positive impact of washback on ‎reading improvement among EFL students. Furthermore, the attitude of learners about TBLA was ‎calculated by employing an “Attitude Questionnaires on Reading”. To analyze the data received ‎from “Attitude Questionnaire” A paired-sample t-test was run. By analyzing the results of ‎quantitative questionnaire it is revealed that learners commonly have a tendency to the application ‎of TBLA in learning and teaching reading skill. Results of the research show that TBLA need to be ‎replaced by traditional assessment procedures since all ‎educational planning always attempts to take ‎full advantage of educational achievements and also improvements. ‎ Manuscript profile