Alkaline phosphatase (ALP) is known as one of the most crucial members of the phosphatase family and encompasses the enormous ability to hydrolyze the phosphate group in various biomolecules; by this, it regulates several events in the pool of biological medium. Owing to its overexpression in various cancer cells, recently, its potential has evolved as a prominent biomarker in cancer research. In this article, we have underlined the recent advances (2019 onwards) of alkaline phosphatase in the arena of emerging cancer theranostics. Herein, we mainly focused on phosphate-locked molecular systems such as peptides, prodrugs, and aggregation-induced emission (AIE)-based molecules. When these theranostics encounter cancer cell-overexpressed ALP, it results in the hydrolysis of the phosphate group, which leads to the release of highly cytotoxic agents along with turn-on fluorophore/pre-existing fluorophore.