The heterogeneity in segmental chain order of grafted polymers was investigated by H-1 multiple-quantum NMR. The measurements were performed on a series of samples of poly(dimethylsiloxane) (PDMS) layers chemically attached to the surface of hydrophilic silica. These grafted PDMS layers consist of partially immobilized chain segments at the PDMS-silica interface and mobile chain portions outside the interface which is supported by measurements of homonuclear double- and triple-quantum buildup curves. These curves reveal a bimodal distribution of the residual dipolar couplings along the PDMS chain. The segmental orientations detected in the interface and mobile regions are related to the average chain length and reflect the competing effects of the surface-induced orientation and chain conformations. The different behavior of the two chain fragments is evident from temperature-dependent measurements.