Assessment has become a relevant part of the teaching and learning process in the past few decades. However, much less importance has been given to the assessment of vocabulary than to other components of the language, such as grammar. As a consequence of this, little attention has been paid to the influence that the methodology used in a vocabulary test can actually have on the results obtained. This study is aimed to explore to what extent test format influences test results in the assessment of vocabulary. For this purpose, First Certificate in English (FCE) students were given three vocabulary tests and an interview was also given to those students who showed some divergence among the results of the three tests. The results indicate that test format can greatly influence the results obtained in vocabulary tests. The findings also suggest that the successive task administrations, evaluating the same key words, do not lead to a better test performance.
