Phonetic perception and lexical access is sensitive to acoustic traces of co-articulatory processes in overlapping neighbouring segments. Longer distance coarticulatory effects, though well documented in production studies, have not been examined with regard to their contribution to lexical access Using an eye-tracking paradigm, we examines whether the acoustic reflex of anticipatory lip-rounding and lip-spreading in initial /S/ in German CC and CCC word onset clusters is used to decide between lexical candidates with phonemically identical onsets prior to the contrasting vowel. The results show a clear effect of the pre-vocalic consonant information, but the effect is not symmetrical for rounded and unrounded /S/. Results are discussed in relation to a phonemic vs. a (demi-)syllabic basis of lexical decisions and markedness theory.