  The 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.
