This study investigates the acoustic properties of vowels in 2 Modern Greek varieties: Standard Modern Greek (SMG) and Cypriot Greek (CG). Both varieties contain in their phonetic inventories the same 5 vowels. Forty-five female speakers between 19 and 29 years old participated in this study: 20 SMG speakers and 25 CG speakers, born and raised in Athens and Nicosia, respectively. Stimuli consisted of a set of nonsense CVCV and VCV words, each containing 1 of the 5 Greek vowels in stressed and unstressed position. Gaining insights from the controlled experimental design, the study sheds light on the gradient effects of vowel variation in Modern Greek. It shows that (1) stressed vowels are more peripheral than unstressed vowels, (2) SMG unstressed /i a u/ vowels are more raised than the corresponding CG vowels, (3) SMG unstressed vowels are shorter than CG unstressed vowels, and (4) SMG /i·u/ are more rounded than the corresponding CG vowels. Moreover, it shows that variation applies to specific subsystems, as it is the unstressed vowels that vary cross-varietally whereas the stressed vowels display only minor differences. The implications of these findings with respect to vowel raising and vowel reduction are discussed.