The present invention is related to the preparation and pharmaceutical use of substituted 3-haloallylamine derivatives as SSAO/VAP-1 inhibitors having the structure of Formula I, as defined in the specification: The invention also relates to methods of using compounds of Formula I, or pharmaceutically acceptable salt or derivatives thereof, for the treatment of a variety of indications, e.g., inflammatory diseases, ocular diseases, fibrotic diseases, diabetes-induced diseases and cancer.