To study the development of selective attention in children a paradigm was developed in which certain features of the stimulus were designated as relevant for task performance while others were defined as incidental. Performance on the central task was assessed as well as later recall of information about the incidental stimuli, and these two measures together provide a basis for inferring selective attention. A major finding is the developmental improvement in children's efficiency of attention deployment. Although incidental learning remains relatively stable from middle childhood to early adolescence, central performance increases markedly. Beyond early adolescence, successful performance on central tasks is accompanied by an inhibition of attention to incidental features. Studies are reviewed which deal with development of task strategies, correlational evidence for the developmental trend, analyses of attention in retardates, and cross-cultural comparisons. A two-stage model of information processing is considered, and it is concluded that this model may account for the various empirical results that have been presented. (DP)