Adsorption of docosanethiol (CH3(CH2)21SH) onto polycrystalline gold from ethanol solution was investigated by nonlinear vibrational spectroscopy. The formation of the self-assembled monolayer (SAM) was monitored by recording of the temporal evolution of the C−H stretching modes. Three different steps with significantly different time scales were identified. The fastest step in the adsorption process is related to the Au−S bond formation. Progressing with a rate constant of 2500−3000 L mol-1 s-1, it is characterized by hydrocarbon chains with a high fraction of gauche kinks. The second step proceeds 3−4 times more slowly and comprises the straightening of the alkane chains. During the first two steps a pronounced band around 2813 cm-1 appears, which is interpreted as mode softening of the C−H vibrations due to the interaction with the substrate. The time scale of the final step is a factor of 35−70 slower than the rate of chain stretching and encompasses the reorientation of the terminal methyl end groups...