The review deals with some medico-biological problems of ferromagnetics applications with the use of physical fields effect (permanent and alternating magnetic fields, high frequency and laser radiation). The main aspects are the following: magnetic fluid as roentgenocontrast, substances; magnetically controlled drug delivery systems; magnetic microspheres with immobilized antibodies; thermo-magnetic cancer surgery; magnetic particles as a tool for subcellular structure investigation; magnetic particles distribution and removal from the organism.