Ether-extracted maltodextrin (MD) powder was surface functionalized under 13.56-MHz RF-SiCl4-plasma conditions, and consecutively in situ aminated and grafted using dichlorodimethylsilane. Survey and high-resolution X-ray photoelectron spectroscopy, FTIR evaluations, fluorescence-labeling technique, SEM, and DTA/TG analyses prove the presence of a graft-copolymer layer on the modified starch-granule surfaces and the existence of a significantly changed surface morphology of the starch granules, as a result of the grafting reactions. The hydrophobic nature of the polydimethylsiloxane-grafted starch and its significantly changed thermal behaviors were also evaluated. Potential applications of modified maltodextrins are discussed.