As language is such a fundamental tool in the determination of a diagnosis and in patient education, non-English-speaking patients and deaf patients often suffer from inferior medical care. Deaf adults and adults studying English as a second language (third- to fifth-grade English-comprehension level) were compared. Participants completed a survey and a test of commonly used medical vocabulary. The two populations did not differ significantly in education level or in vocabulary test scores. Deaf patients were often less able to speak to their physician in their customary language (sign language); as a result, they perceive greater difficulties in expressing themselves to their physicians and reexplain themselves less frequently in response to misunderstandings. It is clear that deaf patients should be recognized as a subset of non-English-speaking patients who are at increased risk for poor physician-patient communication.