This is an acoustic study of prosodic effects on segmental durations with reference to syllable structure, stress, focus and tempo in Greek. Disyllabic nonsense words with one, or two, or three consonants in the initial syllable were examined in stressed/unstressed, focused/unfocused and normal/fast tempo productions in a carrier sentence contexts. The results indicate that: (1) syllabic onset branching has a bigger effect on the consonant than the vowel; (2) stress has a bigger effect on the vowel than the consonant; (3) focus effects are not substantially different from stress effects; and (4) tempo has a rather even effect on consonant and vowel durations.