Tremaine in 1975 found that bilingual hearing children made gains in native and second 1 anguage comprehension when they reached the concrete operational level. Building upon this finding, the present study examined the linguistic and cognitive skills of 59 severe-to-profound and profoundly deaf children between the ages of seven and 12. Through manually coded English, students were administered four Pi ageti an operation a 1 tasks in the areas of conservation, classification, seriation, and numeration and a test of syntactic comprehension. Students and teachers were also given a sociolinguistic questionnaire to determine the hearing status of the child 1 s parents, the age the child learned signs, and the sign consistency at home. Teachers and students showed a high degree of agreement in their responses to this questionnaire.Results indicated that operational deaf children performed significantly better than non-operational deaf children on the test of syntactic comprehension, although both groups of children had poorer English skills and a lower rate of operational thinking than did the younger hearing students in Tremaine•s sample. A relationship was found among operational thinking, age, and IQ of the subjects as well as between age and syntactic skills, but no relationship was indicated between syntactic skills and IQ.Students whose parents consistently signed to them showed greater English syntactic comprehension than did students whose parents signed less consistently. Children with more consistent sign exposure at home also tended to have more advanced operational skills, though not to a statistically significant degree. In both operational level and English syntactic skills, a slight advantage was found for those children using American Sign Language at home rather than manually coded English. This finding may be explained by the greater degree of sign consistency likely to be experienced by those children whose deaf parents use American Sign Language. Finally, a multiple regression analysis indicated that over half of the total variability on the test of syntactic comprehension could be predicted from success or failure on two of the operational tasks (numeration and seriation) and the child's overall signing ability, with age and IQ much poorer predictors of English skills.