This study compared the conceptual rule learning performance of normal and learning disabled children. Subjects for the study were 18 normal and 18 learning disabled children with mean ages of 9.4 and 9.3 years and mean IQ scores of 103.1 and 101.6 respectively. The children were matched for age, IQ, sex and race. Four types of rules (affirmation, conjunction, disjunction, conditional) and the use of familiar and nonfamiliar shapes were used to test the children's ability to identify relevant attributes and to apply the necessary concept formation rule. The effect of changes in rule complexity was also analyzed. The task for the study involved the identification of positive and negative instances of a concept involving a pair of relevant attributes, one of which was always shape. Results from the study indicated that rule learning was retarded by increasing rule complexity for all children. Learning disabled children, however, demonstrated significantly poorer performance than normal children on all tasks. Shape familiarity increased the success of normal children on the most difficult problems but had no corresponding effect on learning disabled children. The results are discussed in terms of possible processing deficiencies and the difficulty inherent in the comprehension of negative instances in concept formation tasks. (BD)