Disclosed is a process for producing a water-resistant polarizing film that can solve a problem involved in a conventional technique. A conventional polarizing film with an organic coloring matter oriented therein uses an organic coloring matter having a sulfonic acid base comprising a sulfonic acid ion bonded to a monovalent cation. The conventional polarizing film has poor water resistance because the sulfonic acid base in the organic coloring matter is dissolved in water. On the other hand, a water-resistant polarizing film can be formed by replacing a monovalent cation in the sulfonic acid base with a water-insoluble divalent cation.Treatment for imparting water resistance involves a problem of a lowered dichroic ratio. In order to provide a water-resistant polarizing film free from a lowered dichroic ratio, the positional relationship between adjacent sulfonic acid groups or sulfonic acid bases within the organic coloring matter used in the polarizing film, which is to be subjected to the treatment for imparting water resistance, is important. The process for producing a water-resistant polarizing film according to the present invention is characterized in that the polarizing film before the treatment for imparting water resistance contains an organic coloring matter of an azo compound (20) represented by the following general formula (1) or (2).