A method for producing 1-chloro-3,3,3-trifluoropropene efficiently from an intermediate product having a low reactivity is provided. A method for producing trans-1-chloro-3,3,3-trifluoropropene comprising reacting a halogenated hydrocarbon compound having 3 carbon atoms represented by Formula (1) shown below in a gas phase with hydrogen fluoride in the presence of chlorine is provided. C3HXClYFZ (1) wherein X is 2 or 3; and when X=2, Y is an integer from 1 to 4, Z is an integer from 0 to 3, and Y+Z=4; and when X=3, Y is an integer from 1 to 5, Z is an integer from 0 to 4, and Y+Z=5; provided that Formula (1) shown above represents a halogenated hydrocarbon compound having 3 carbon atoms excluding trans-1-chloro-3,3,3-trifluoropropene.