Assessment has long been regarded as an integral part of the learning process. In the field of assessment, washback effect is understood as the impact of tests (or any assessment procedure) on the learner, the learning process, teachers, or such like. Thus, the purpose of the present study was to determine the washback effect of two different types of assessment procedures, namely, a traditional test and an alternative assessment procedure (a project) in an intact sample of 32 seventh-grade students, from a subsidised school in Chile. Through a mix-methods approach, quantitative data were gathered through a self-reported-washback survey, administered after a traditional test was given to the participants and after an English language project was carried out; qualitative data regarding the perceived effects caused by the test and the language project were gathered through a focus group interview. A series of t-tests was performed for quantitative data gathered through the washback surveys, while content analysis was used for the qualitative data emerging from the focus group interview. The results suggest that both procedures are positively valued, with the alternative assessment procedure being held in higher regard as far as motivation, anxiety and strategy use are concerned, as became evident in the focus group interview.