Three experiments with object-manipulation tasks examined the effect of object structure on 14-, 18-, and 22-month-olds' categorization. In Experiment 1, categorization of animals and vehicles was tested when object structure was normal and when it was violated by moving parts (legs or wheels) into a novel configuration. In Experiment 2, categorization of animals, vehicles, and furniture was examined when object structure was modified in orientation (e.g., legs inverted) or in configuration (e.g., legs at tangential angles). In Experiment 3, infants' attention to texture in categorization was tested. The results of the studies showed that 14- to 22-month-olds attend to object parts and structural configuration to categorize and that they do not attend to object texture. There is a perceptual basis for early categorization at the superordinate-like level, and infants are constrained in the parts and object structures they recognize in this process.