Two metal supported solid oxide fuel cells (active area 16 cm(2)) with nanostructured Ni:GDC infiltrated anodes, possessing different anode and support microstructures were studied in respect to sulfur tolerance at an operating temperature of 650 degrees C. The studied MS-SOFCs are based on ferretic stainless steel (FeCr) and showed excellent performance characteristics at 650 degrees C with fuel utilization corrected area specific resistances of 0.35 Omega cm(2) and 0.7 Omega cm(2) respectively. The sulfur tolerance testing was performed by periodic addition of 2, 5, and 10 ppm H2S in hydrogen based fuel under galvanostatic operation at a current load of 0.25 Acm(-2). The results were compared with literature on the sulfur tolerance of conventional SOFC Ni/YSZ cermet anode. The comparison in terms of absolute cell resistance increase and relative anode polarization resistance increase indicates, that the nanostructured Ni: GDC MS-SOFC based anode is significantly more sulfur tolerant than the conventional Ni/YSZ cermet anode. Furthermore, it was shown that the believed extension of the electrochemical three-phase-boundary reaction zone in the presence of GDC must be very limited and cannot account for the higher sulfur tolerance of GDC modified SOFC anodes. (C) The Author(s) 2016. Published by ECS. All rights reserved.