Carbon dots have been employed as visual detection sensors for anticancer drugs. In addition, carbon dots are potential candidates in cancer nano-therapy due to their photostability, excitation-dependent emission, and facile surface functionalization. Carbon dots function by binding to anticancer drug, then target the tumor cells and deliver drug molecules at cell surface, leading to cell death. The intrinsic fluorescence, coupled with surface properties and the smaller size of carbon dots, lead to potential applications in bioimaging. Carbon dots can induce DNA damage to tumor cells during cancer therapy. This chapter outlines the techniques for detecting anti-neoplastic drugs utilizing carbon dots as sensing materials and highlights their potential medicinal role in cancer theranostic by inhibiting cell migration and suppressing cancer cell viability.