We present the results of an empirical test of the hypothesis that transfer of orthographic processing to reading occurs when the scripts under acquisition are written with the same unit (specifically, the same alphabet). We tested 97 Spanish-English bilingual children in Grades 4 and 7. We measured mother's education level, verbal and nonverbal abilities, rapid automatised naming and phonological awareness as control variables, as well as orthographic processing and reading in both of the children's languages. First, there was a relationship between orthographic processing and reading within both English and Spanish reading, a finding that is novel for the more transparent script of Spanish. Second, orthographic processing assessed in Spanish was related to English reading, even after substantive controls. This pattern of results offers support for the idea that orthographic processing transfers to reading across languages, when the scripts are written with the same unit. (Contains 3 tables and 3 notes.)