This study investigated visuo-orthographic knowledge in deaf readers of French compared to age-matched hearing subjects. More specifically, we were interested in knowledge related to the legal position of double consonants and to the fact that double consonants are much more frequent than double vowels in written French. We used a word-likeness choice task in which subjects had to determine which of two pseudo-words most resembled a real word in written French (e.g., "fellut" or "felutt"). The participants were 24 deaf students aged 10 to 18 and 24 matched hearing students. The main results indicate that deaf readers develop the targeted knowledge, but to a lesser extent than hearing controls. Different avenues are proposed to explain this difference. (Contains 6 tables and 4 notes.)