A sample of 8-to 12-year-old nonhyperactive children of normal intelligence with the DSM-III-R diagnosis of pervasive developmental disorder not otherwise specified (PDDNOS) completed two selective attention tasks. Following a linear stage model of information processing, it was demonstrated that these PDDNOS children did not show a deficit in the encoding and decision stages of information processing. Moreover, they did not exhibit a focused attention deficit when asked to ignore irrelevant information. They did, however, appear to exhibit a divided attention deficit that could be pinpointed to the stage of serial comparison: Compared to an age-matched group of normal children, the rate of carrying out serial comparisons decreased more sharply when the number of stimuli to be compared (cognitive load) was increased.