Dyes are widely used to colour products in textile, leather tanning, cosmetics, pigment and many other industries. Effluents discharged from these industries cause potential hazards to environment and human health. Hence, the removal of dyes from water/wastewater has gained a huge attention in recent years. So far, biological, chemical and physical methods are the traditional techniques, of which adsorption is found to be a more effective and cheap method for removing dyes. Nanotechnology has applied successfully to the water/wastewater treatment and emerged as a fast-developing promising field. Application of nanomaterials (NMs) in dyes removal seems to be an efficient way. In this review, extensive literature information was presented with regard to dyes, its classification and toxicity, different methods for dyes removal including the removal of dyes by NMs. It is evident from the literature survey that NMs have shown good capability for the removal of dyes.