This paper investigates the popular belief that children's attitudes toward school and particular subjects have a positive relationship with their school and subject achievement. Definitions of attitude by L. L. Thurstone, L. W. Doob, and M. Fishbein are presented as a basis for the investigation. The difficulties involved in assessing attitudes are revealed through examples which illustrate the interrelationship among expressed opinions, beliefs and intentions, behavior (responses), and actual attitudes. Empirical studies which examine the correlations between attitude and achievement are discussed. The paper proposes that it is probable that an observed relationship between attitude and achievement does not necessarily exist. The paper concludes with the implications of the last statement for educators. These implications include the need to study more carefully the reasons why attitude is not a strong correlate of achievement. A second implication is that educators should not be too hasty nor too sure in making assessments of attitudes from students' expressed opinions or overt behavior. (JBW)