Variation and distribution of Tanrilla semicincta are discussed. This species exhibits pattern dimorphism. One phase has a banded dorsal pattern and the other a striped dorsal pattern. Variation in scutellation is described. This species is known to occur along the Caribbean coastal regions of Colombia and Venezuela. Purported occurrence of this snake in Panama is discounted. Relationships of T. seinicincta with other banded species of Tantilla are discussed and a key to those species is provided.