<p>Organic compounds are used to improve people’s quality of life in many ways and play a crucial part in numerous biological and chemical activities. Schiff bases and their complexes have received more attention from researchers in recent years. Sulfur and oxygen containing semicarbazide and thiosemicarbazide Schiff base ligands possess important character and show significant biological activities. In order to analyze their biological activities, many researchers have synthesized a derivative of Schiff bases as targeted molecules. Their derivatives have shown antimalarial, antibacterial, antifungal, anticancer, antiviral, and other biological properties. One of the best approaches for synthesizing thiosemicarbazide/ semicarbazide derivatives is adding hydrazides to various isocyanates and isothiocyanates. Metal chelating complexes and anticorrosion agents are also used as a precursor for synthesizing several SB’s. Their derivatives and metal chelates in the drug industry are the subjects of study. The structures of thiosemicarbazide/semicarbazide derivatives and their transition metals were evaluated by different spectroscopic techniques. This review covers the synthesis and biological applications of thiosemicarbazide/semicarbazide derivatives and their transition metal complexes in last 20 years.</p>