It appears that the extensive use of SILL by language teachers, practitioners andresearchers is often motivated by tradition and convenience rather than resultingfrom a sound methodological design and subsequent execution. Basic questions suchas the representativity of the sample, the procedure of data collection, the suitabilityof the instrument for different age spans or cultural backgrounds are rarelyaddressed. The major purpose of this paper is to present the conditions under whicha Greek version of SILL achieve the intended objectives of reliability and validity forthe Greek setting