Most studies on the Stroop effect (unintentional automatic word processing) have been restricted to English speakers using vocal responses. Little is known about this effect with deaf signers. The study compared Stroop task responses among four different samples: deaf participants from a Japanese-language environment and from an English-language environment; and hearing individuals from Japan and from Australia. Color words were prepared in both English and Japanese and were presented in three conditions: congruent (e.g., the word red printed in red), incongruent (e.g., red printed in blue), and neutral. The magnitude of the effect was greater with the deaf participants than with the hearing participants. The deaf individuals experienced more interference in English than in Japanese.