Caecilians are poorly studied compared to the more familiar amphibians, frogs and salamanders, and this is especially true of the larval stage. In basal members of all three groups, we know that the nasal sac is remodeled considerably during metamorphosis, allowing a transition from aquatic (water) smelling to terrestrial (air) smelling. Yet despite this general similarity, previous work suggests that significant differences exist among larvae of the three groups. Using paraffin embedding and traditional histology, among other methods, we examined the morphology of the larval olfactory organ of the Koh Tao Island caecilian (Ichthyophis kohtaoensis). In the caecilian larva the external naris gives way to a short vestibule; this widens into the principal cavity (PC) which continues to widen until about midway through the organ. The vomeronasal organ (VNO) lies ventrolaterally; it also begins midway and runs posteriorly along the ventrolateral PC. As one approaches the choana, the VNO shifts medially and the choanal slime sac (CSS) appears. The PC, the VNO, and the CSS all open posteriorly into the choana, which opens directly into the buccal cavity. As in frog and salamander larvae, backflow is prevented by the presence of a choanal valve. Sensory epithelium is found in most of the PC, and on the ventral side of the VNO, while the remainder of the olfactory organ, including the CSS, contains non-sensory epithelium. Overall, while the olfactory organs of larval frogs, salamanders, and caecilians are shaped quite differently, the composition of the sensory epithelium appears similar. Understanding the ontogeny of the olfactory organ in a basal caecilian like I. kohtaoensis will help us to further reconstruct the primitive condition of the olfactory organ of amphibians, and therefore of tetrapods in general.