This study was concerned with the effect of situational frequency manipulations on subsequent discrimination learning. The subjects were 104 fourth-grade children attending two elementary schools located in middle-class residential areas. Twenty-six subjects were randomly assigned to each of two picture conditions. The other 52 subjects were randomly divided between two word conditions. The learning of the discrimination list consisted of picture pairs preceded by either relevant or irrelevant prefamiliarization training. In the relevant prefamiliarization condition, subjects were pre-exposed to the pictures which occurred in the discrimination task. In the irrelevant conditions, subjects were exposed to materials unrelated to the discrimination-task pictures. In the experiment utilizing verbal materials, subjects learned a discrimination list consisting of word pairs after they received either relevant or irrelevant prefamiliarization training. A significant negative effect of prefamiliarization was found in both experiments. It was concluded that the effect of stimulus prefamiliarization generalizes across stimulus materials (pictures and words) and across age levels. (WR)