Krabbe disease or globoid cell leukodystrophy (GLD) is a severe lysosomal disorder resulting from the deficiency of galactocerebrosidase (GALC) activity. This deficiency results in the insufficient catabolism of several galactolipids that are important in the production of normal myelin. Since the cloning of the human GALC cDNA and gene many disease-causing and polymorphic changes have been identified. This autosomal recessive disease has been reported to occur in several animal species, and recently the murine and canine GALC genes have been cloned. We now describe the cloning of the GALC cDNA and gene from the rhesus monkey and the identification of the mutation causing GLD in this species. The nucleotide sequence of the coding region and the gene organization were nearly identical to human. The deduced amino acid sequence of the monkey GALC was compared to the human, dog, and mouse, and it was found to be 97, 87, and 83% identical, respectively. The mutation causing GLD in the rhesus monkey is a deletion of AC corresponding to cDNA positions 387 and 388 in exon 4. This results in a frame shift and a stop codon after 46 nucleotides. A rapid method to detect this mutation was developed, and when 45 monkeys from this colony were tested, 22 were found to be carriers. The availability of this nonhuman primate model of GLD will provide unique opportunities to evaluate treatment for this severe disease.