The lectin binding characteristics of goldfish retinal explants were examined by fluoresence microscopy. Neurites grown out from cultured retinal explants were found to bind concanavalin A, wheat germ agglutinin and ricin (agglutinin). The effects of tissue fixation on lectin binding to retinal explant neurites suggest that glycolipids may constitute the predominant ricin binding sites. A reduction in labeling with wheat germ agglutinin following sialidase treatment indicates preferential binding of the lectin to sialic acid residues in the neurite membrane. Neurite morphology was unaltered by brief exposure to concanavalin A or wheat germ agglutinin, while ricin caused a marked deteriaration.