Assessment of lexical/semantic knowledge is performed with a variety of tests varying in response requirements. The present study exemplifies the application of modern statistical approaches in the adaptation and assessment of the psychometric properties of the "Peabody Picture Vocabulary Test--Revised" (PPVT-R) Greek. Confirmatory factor analyses applied to data from a large sample of elementary school students (N = 585) indicated the existence of a single vocabulary dimension and differential item functioning procedures pointed to minimal bias due to gender or ethnic group. Rasch model-derived indices of item difficulty and discrimination were used to develop a short form of the test, which was administered to a second sample of 900 students. Convergent and discriminant validity were assessed through comparisons with the "Wechsler Intelligence Scales for Children"--III Vocabulary and Block design subtests. Short- and long-term stability of individual scores over a 6-month period were very high, and the utility of the test as part of routine educational assessment is attested by its strong longitudinal predictive value with reading comprehension measures. It is concluded that the Greek version of the PPVT-R constitutes a reliable and valid assessment of vocabulary for Greek students and immigrants who speak Greek. (Contains 4 tables and 6 figures.)