The nano-particles of hematite (α-Fe₂O₃) has so many different properties like magnetism, hydrophilic, non-toxic, high chemical stability, chemical and biological compatibility and high potential in applications of environmental remediation. In this paper, we report the simple, promising, improved synthesis of hematite/alginate nanocomposites and characterized by XRD, SEM, FTIR and UV–visible. Hematite/alginate (AG) beads of diameter 2–3 mm were prepared and used for adsorption/removal of organic dyes like methylene blue. The removal of the 25 ppm MB dye was obtained ∼100% within 40 min at pH 9 using 1 g/L hematite/AG beads nanocomposite at room temperature. All the adsorption parameters have been also discussed by linear fitting with first-order reaction.