Microwave-initiated synthesis of polyacrylamide-grafted sodium alginate, a graft copolymer with wide variety of applications has been reported in this study. The effect of reaction parameters (i.e., irradiation time and monomer concentration) onto the percentage grafting has been investigated. The resulting polymer has been characterized by a variety of characterization techniques such as intrinsic viscosity measurement, Fourier transform infrared spectra, C-13 NMR spectra, elemental analysis, thermogravimetric analysis, molecular weight determination using static light scattering analysis, and scanning electron micrographs. Further, the flocculation efficiency of this graft copolymer has been investigated in coal suspension. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 63-71, 2010