Biomimetic calcium phosphate apatites, analogous to bone mineral, may now be produced synthetically. Their intrinsic biocompatibility and the nanometer dimensions of their constitutive crystals not only allow one to envision applications in bone tissue regeneration, but also in other medical fields such as nanomedicine, and in particular in view of cell diagnosis.In this mini-review, we look back at 10 years of our dedicated research, and summarize the main advances made in terms of preparation, physical-chemical characterizations and biological evaluations of colloidal formulations of biomimetic apatite-based nanoparticles, which we illustrate here with the angle of cancer diagnosis. The confirmed exceptional biocompatibility of these engineered nanoparticles, associated to the possibility to confer them luminescence properties by way of controlled lanthanide doping, and their capacity to be internalized by cells, including with cancer cell addressing abilities (shown here as a proof of concept), underline that biomimetic apatite-based colloidal nanoparticles are particularly promising for nanomedicine applications, for example related to diseased cells diagnosis. Multidisciplinary research on these functional nanoparticles, initiated as described here, has now generated emulation in the scientific community where the concept of apatite nanoparticles for nanomedicine is being, gratifyingly, appropriated.