Student rights to freedom of speech and the legitimate degrees of control available to principals are discussed in this paper. An overview of pertinent federal litigation focuses on two landmark cases involving oral and written speech, respectively: Bethel School District #403 v. Fraser; and Hazelwood School District v. Kuhlmeier. A conclusion is that principal effectiveness depends partially on knowledge of community standards of acceptable speech and on legal awareness. An addendum describes the Supreme Court decision in June 1990 of Westside Schools v. Mergens, which provides a new degree of student freedom and imposes a burden of conformity on public schools. (9 references) (LMI)