Lanthanide luminescent bioprobes (LLBs) are amongst the most sensitive luminescent probes because their excited states are long-lived, which allows time-resolved detection (TRD) of their luminescence, boosting the signal-to-noise ratio and the sensitivity; in addition they are fairly insensitive to photobleaching since lanthanide ions are good quenchers of triplet states. Applications of LLBs to immunoassays, DNA analysis, ligand binding assays, analyte sensing, and cellular imaging are reviewed. Future developments in immunohistochemistry, targeting of specific organelles, lab-on-a-chip technology, and instrumental design are evoked