Immunomorphologic assessment of percutaneous renal biopsy became a standard procedure for establishing diagnosis in kidney disease in parallel with routine haematoxylin and eosin stained paraffin sections. Among various immunomorphologic techniques, direct immunofluorescence of cryosections with a panel of fluorochrome labelled polyclonal or monoclonal antibodies to various serum proteins turned out to be the most reliable and rapid diagnostic procedure. The panel of antibodies may be expanded to include those to microbial or tumour antigens, when needed. The authors specify major advantages of immunofluorescence for such task and potential pitfalls in the case of nonspecific staining. In the next step, various types of fluorescence within renal structures are confronted with particular kidney disorders. Special attention is paid to various types of glomerulonephritis. Lesions in transplanted kidney are also discussed and the role of deposition of C4d complement component along peritubular capillaries is underlined as the evidence of humoral anti-graft reaction. The article is supplemented with a detailed technical procedure for performing of immunofluorescent reaction and evaluation of kidney biopsy, including several control steps.