Authors describe their own method for the investigation of needle-biopsy of kidney using light-, and electron microscopy and immunofluorescent technique as well. Small pieces are cut from both end of the needle-biopsy-cylinder and are embedded for electron microscopy. From the larger central part of it cryostat sections are made (at -20 degrees C) for the immunofluorescent study. Afterwards the piece of tissue remained can be fixed in formaldehyde and embedded in paraffin for light microscopic investigation. All three methods can be carried out even when having a 6 mm long needle-biopsy specimen.