A substantial body of research has noted morphological priming effects in visual word recognition in deep orthographies, but it is still unclear whether similar effects exist in transparent orthographies. In the present experiment, we investigated the development of morphological decomposition in visual word recognition in the phonologically highly transparent and morphologically rich Bosnian orthography by exploiting the fact that Bosnian is written in two different scripts: Everyday texts are typically presented in Latin, but all children learn and practice reading in Cyrillic script from Grade 3 on. Students in four different age groups (Grades 4, 6, 8, and university students) were asked to read aloud singular target nouns that were preceded by different primes. Three prime types were presented in Latin script: morphologically related (plural) words, morphologically unrelated, but orthographically similar words and unrelated words. We also presented the morphologically related and unrelated primes in Cyrillic, reducing the visual-orthographic overlap between prime and target. In Latin, response times were lower in the orthographic than the unrelated prime conditions and again lower in the morphologically related than the orthographically similar prime condition, irrespective of prime duration (50 and 250 ms). We did not find any evidence for interactions with grade level, suggesting that morphological decomposition is established by Grade 4. Cyrillic primes also induced significant (though smaller) morphological priming effects suggesting that morphemes are units of meaning even during early written word processing.