We report on the temperature stability of N@C-60 peapods using electron spin resonance. The atomic nitrogen escapes at higher temperatures in the peapod than in the crystalline form. We also report on the synthesis of novel magnetic fullerene peapod, a fullerene with an attached pyridine-nitroxide spin-label. This molecule can be the ultimate inner spin label for the SWCNTs as it is available in microscopic amounts and is not air sensitive. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim