NZ 595482 Disclosed is the use of tris(8-quinolinolato)gallium(III) or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for treating or preventing osteoporosis. Also disclosed is the use of tris(8-quinolinolato)gallium(III) or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for preventing or delaying the onset of bone metastasis of cancer.