The structure of zeolite UTM-1 has been determined from synchrotron X-ray powder diffraction pattern by direct methods and Rietveld refinement. The framework of UTM-1 consists of pocket-like cages connected by sharing eight-membered rings forming one-dimensional channels. The structure can be completely described by the assembly of chains of 5(8) cages. Identical chains are found in MFI topology; the zeolites UTM-1 and ZSM-5 are distinguished from each another by the way the chains are assembled.