Phthalocyanine dyes are one of the major categories of reactive dyes. They are water-soluble metal complexes, mainly containing copper, that are resistant to bacterial degradation under aеrobic and anaerobic conditions. In this review article, the authors present the removal of RB21 phthalocyanine dye in aqueous solution by adsorption based on the literature. Therefore, an exhaustive list of various adsorbents has been compiled here. Additionally, the performance of several adsorbents under different physico-chemical process parameters and their comparative adsorption capacity towards the adsorption of RB21 dye was also presented. Affective adsorption factors for the dye such as solution pH, initial dye concentration, adsorbent dosage and temperature are also included.