The current study investigates reading aloud words in Persian, a language that does not mark all its vowels in the script. Behaviorally, a "masked onset priming effect" (MOPE) was revealed for transparent words, with faster speech onset latencies in the phoneme-matching condition (i.e. phonological prime and target onset overlap; e.g. [image omitted] /[image omitted]/; "year" - [image omitted]/"sot"/; "voice") than the phoneme-mismatching condition (e.g. [image omitted]/[image omitted] :b/ "swing" - [image omitted]/"sot"/; "voice"). For opaque target words (e.g. [image omitted]/"solh"/; "peace"), no such effect was found. However, event-related potentials (ERPs) did reveal an amplitude difference between the two prime conditions in the 80-160 ms time window for transparent as well as opaque words. Only for the former, this effect continued into the 300-480 ms time window. This finding constrains the time course of the MOPE and suggests the simultaneous activation of both the non-lexical grapheme-to-phoneme and the lexical route in the "dual-route cascaded" (DRC) "model". (Contains 1 figure.)