2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/11920The four known molecular absorption line systems at redshifts z$=$0.25--0.89 are discussed. Two of the systems originate in the galaxy hosting the `background' AGN, while in two cases the absorption occurs in truely intervening galaxies. Indirect evidence for the existence of very small scale structure in the molecular ISM is presented. A new absorption line at z$=$0.89 towards PKS1830--211 opens up interesting possibilities to accurately derive the mass of the lensing galaxy.8 pages, 3 figures, to be published in the Proceedings of the Green Bank Symposia ``Highly Redshifted Radio Lines'' Oct 9-11 1997, eds. C. Carilli, et alAstrophysicstext