Sex role influences a diverse range of social behaviors. Since language behavior is central to social interaction, sex role was expected to influence language behavior. Since members of the two sexes experience varying biosocial realities, and since language is a system of communication about realities, language behavior of men and women was expected to differ. Case refers to a system of deep structure constructs which define the relational meaning of a nominal unit to the verb and any other nominal units within a simplex sentence. Hypotheses about cases were deduced from corresponding features of sex role behaviors and case categories. Cases and gender were measured from texts made from videotapes of teachers in classrooms. Reconstruction, a method of inserting grammatically and contextually implicit information into the verbal exchange and classifying the resulting communication into simplex sentences and lexical units, was used to process the language data. Women produced a significantly greater proportion of explicit participative cases than men, thus demonstrating their greater concern with internal psychological states. The greater involvement of men with implementation of action by means of objects was shown by their greater use of instrumental and source cases. Women used significantly more instances of the purposive case. Men produced a significantly greater proportion of objective cases, thus verbally emphasizing things and particularly things acted upon. Agentive and locative cases failed to yield a difference for case realizations by men and women. Implications and conclusions were discussed.