The mono-protonated cyclic tetraamine in the title compound, C11H27N4.ClO4-.H2O, has the four N atoms in a tetrahedrally twisted [+/-0.13(1
)Angstrom] square arrangement, The protonated N5 atom forms the only i
ntracyclic hydrogen bond (N5 - H ... N1); all other NH groups form hyd
rogen bonds to water or perchlorate O atoms.