Objective: NCAM + cells with dendritic morphology are rarely present in normal renal interstitium. The aim of this study was to evaluate presence of NCAM + cells in kidney biopsies of different renal diseases with and without interstitial fibrosis (IF). Further immunophenotyping of NCAM + renal interstitial cells was performed. Method: 97 kidney biopsies, after routine diagnosis, were stained applying antibodies against NCAM clone123C3.D5 or cloneEric1. For double immunofluorescence, antibodies against NCAM cloneEP2567Y and FGFR1, alpha5beta1 integrin, alphaSMA, cadherin9, cadherin11 were used. By RPCR, different NCAM isoforms (120, 140, 180) were detected using specific primers in 11 renal tissues with and without IF. Results: NCAM + interstitial cells were identified in 48 cases: 69 % lupus nephritis, 64 % focal segmental glomerulosclerosis, 64 % IgA nephropathy, 55 % membranoproliferative glomerulonephritis, 50 % membranous glomerulonephritis. NCAM + cells coexpressed FGFR1 and alpha5beta1 integrin, and were increased in IF. NCAM + cells did not coexpress alphaSMA, cadherin9 and cadherin11, although they were closely colocalised. All normal renal tissues tested for RPCR showed presence of all NCAM isoforms, however NCAM180 lacked in some tissues with IF. Conclusion: NCAM + renal interstitial cells coexpress FGFR1 and alpha5beta1 integrin and are increased in renal diseases with IF, mostly in diffuse proliferative lupus nephritis. In contrast to normal kidneys, in renal tissue with IF NCAM180 is present in a lesser extent.