Different patterns of labeling were obtained in regenerating rat sciatic nerve after incorporation of labeled, fast-transported protein by motor or sensory axons. In motor axons incorporation of label occurred principally at the distal end of the regenerating fibers, whereas in sensory axons incorporation occurred uniformly along the entire length of nerve between the original site of injury and the most rapidly growing tips. This difference is not a consequence of the different types of axonal trauma used to provoke regeneration but may reflect a less synchronous outgrowth of sensory axons after injury. © 1979.