Abstract: The present invention concerns novel pharmaceutically active compounds, pharmaceutical compositions containing the same, the compounds for use as medicaments, and use of the compounds for the manufacture of specific medicaments. The present invention also concerns a method of treatment involving administration of the compounds. Specifically, the compounds are pharmaceutically acceptable salts of tolterodine or hydroxytolterodine, wherein the salt is of an acid selected from the group consisting of aliphatic mono- and dicarboxylic acids comprising from 7 to 24 carbon atoms, alkanedisulfonic acids comprising from 2 to 4 carbon atoms, naphthoic acid derivatives comprising from 11 to 27 carbon atoms, maleic acid and fumaric acid.