We have studied the decay dynamics of visible photoluminescence (PL) from nanometer-sized Si crystallites fabricated by electrochemical etching of single crystalline Si and laser-breakdown of SiH 4 gas. In two types of Si crystallites, the slow decay behavior of red PL is characterized by a stretched exponential function. The temperature dependence of the PL decay rate is similar to that of variable-range hopping of carriers in two-dimensional systems. It is concluded that the slow decay PL is caused by the hopping-limited recombination in surface states of nanocrystallines. PACS: 73.20.Dx; 78.66.-w; 78.90.+t