In the advent of GaN photonic devices, there is renewed interest in looking at the growth of nanostructures of III-Nitrides that can yield novel properties. To grow a high density of self-assembled GaN nanostructures on a large scale, there is a need to use templates with well-defined nanometer scale features. The Si (5 5 12)-2 × 1 surface is a naturally faceted stable surface that has several nanotrenches of (225) and (337) with a large unit cell of 5.35 × 0.77 nm2. In this work we present here, the first report on the X-ray photoelectron spectroscopy study of the adsorption kinetics of Ga on Si (5 5 12)-2 × 1 reconstructed surface. The uptake curve which is the plot of the ratio of Ga (2 p ) to Si (2 p ) intensity with deposition time, shows that Ga grows in a Stranski–Krastnov growth mode on Si (5 5 12) surface. The core level spectra of Si (2 p ) and Ga (2 p ) have been deconvoluted to see the evolution of the interface during the adsorption process of Ga . The valence-band spectra show the modification of the electronic structure and the secondary electron emission spectra yield the change in work function during Ga adsorption. Correlating the electronic and structural aspects of the interface formation results the study demonstrates the possibility of integrating Si and group III-nitride technologies while exploiting the novel properties due to reduced dimensions.