This study investigated the structural and temporal relationship between graphemic and phonemic processing by means of a cross-modal priming procedure. Subjects made a forced choice on the identity of the vowel in an auditorily presented syllable. To determine if and when phonemic representations are automatically activated by graphemes, visual letter primes were presented before, during, or after presentation of the syllable. in the indirect priming condition, the relationship (congruent/incongruent) between the letter and the consonant adjacent to the vowel was manipulated, whereas in the direct priming condition that between the letter and the target vowel itself was varied. in two indirect priming experiments faster reaction times were obtained over the entire range of SOAs tested when the prime was congruent with the consonant of the syllable, than when it was not. in a third direct priming experiment SOA-dependent facilitation effects were found with respect to a bimodal baseline-condition when the prime was congruent with the target vowel, and inhibition effects when it was congruent with the competing target vowel. The results support the hypothesis of automatic grapheme-to-phoneme activation before word recognition.