In the present study, the acoustic properties associated with stress in compounds in Modern Greek are investigated. Specifically, the claim that Greek compounds consist of a single Phonological Word is tested since it has been argued, based on impressionistic observations, that compounds only contain a single stressed syllable. This claim about Greek is in contrast with the pattern observed in many other languages, including English, where compounds consist of multiple Phonological Words each of which retains its own word stress. Data from 6 native speakers producing 10 adjective-noun phrases and corresponding novel compounds are examined. The analysis focuses on F0 properties given that a recent study of prominence patterns in Greek has demonstrated that F0 is the main property of stress; however, data on duration, intensity and vowel centralization, the other properties commonly associated with stress are also presented. The results provide systematic confirmation of the impressionistic claims about Greek compounds having only a single stress in that the acoustic properties of the stressed vowel of the first word of compounds found to be reduced compared to the corresponding word of phrases. The second word in both constructions was similar in all measurements.