Carbon-carbon bond activation by subsurface hydrogen has been observed for adsorbed cyclopropane at 170 K on the Ni(lll) surface. Propane was the dominant product, and no multiple C-C bond activation processes were observed. Cyclopropane desorbs at 124 K from both the clean and the hydrogen-coadsorbed Ni(lll) surface. Neither coadsorbed hydrogen nor disproportionation induces propane formation. These observations are consistent with previous results that energetic forms of hydrogen are necessary to activate the C-C bond even in strained cyclopropane under ultrahigh-vacuum conditions.