A picture-word interference paradigm with visually presented distractors was used to investigate the independent effects of orthographic and phonological facilitation on Mandarin monosyllabic word production. Both the stimulus-onset asynchrony (SOA) and the picture-word relationship along different lexical dimensions were varied. We observed a pure orthographic facilitation effect and a pure phonological facilitation effect, and found that the patterns of orthographic and phonological facilitation were different. Of most interest, the additive effects of orthographic and phonological facilitation at -150-ms and 0-ms SOAs indicated that the orthographic effect was largely independent of the phonological effect on spoken picture naming. We argue that the present findings are useful for constraining theoretical models of language production and contend that theoretical models of word production need to consider independent effects of orthography and phonology on picture naming, at least in Chinese. (Contains 2 tables and 2 figures.)