The public's reasons for encouraging the competency testing of teachers are discussed, as well as arguments against teacher testing. Testing activities or considered legislation in Florida, Mississippi, North Carolina, South Carolina, Louisiana, Tennessee, Georgia, Arkansas, Virginia, Iowa, Oklahoma, Arizona, Wisconsin, and New York are briefly outlined; as are local district activities in Pinellas County, Florida; Austin and Dallas, Texas; Torrington, Connecticut; Mobile, Alabama; Prince Georges and Montgomery Counties, Maryland; Emporia, Kansas; Richmond, Virginia; New York and Buffalo, New York; Chicago, Illinois; and Salem, Oregon. Two major arguments in support of teacher competency testing are explored: the signs that significant numbers of teachers are incompetent; and the failure of current teacher education, certification, selection, and evaluation procedures to solve these problems. Problems associated with testing are also discussed: (1) uncertainty exists as to which criteria validly measure teacher competence teacher competence; (2) tests can only screen out the very worst teachers; human judgments are still required; and (3) tests may not legally discriminate against teacher applicants. It is concluded that teacher testing may be part of a solution to current problems, if testing is improved in conjunction with certain changes in teacher education and educational administration. (GDC)