Abstract: 2-[.omega.-(3-thiazolidinyl)alkoxy]pyridine compounds, also substituted in the 5-position by methyl, chlorine, bromine, or iodine, and acid-addition salts thereof, which are useful as antiradiation agents, and their production by reacting a 2-pyridyloxyalkylaminoethanethiol with formaldehyde or a reactive derivative thereof.