Herein, we report the synthesis of 4H- [1,2,3]thiadiazolo[4,5b]indole derivatives along with their pharmacological activity against different Gram-(+ ve), Gram-(À ve) and fungal strains. Structures of all the compounds were elucidated by NMR, HRMS, LC-MS and IR analysis methods. The biological studies revealed that 4H-[1,2,3]thiadiazolo[4,5-b]indole and 5-nitro-4H-[1,2,3]thiadiazolo[4,5-b]indole compounds possess good antifungal activity with IC50 values of 10.8 � 2.2, 16.0 � 0.9 and MIC values of 25 and 36, respectively. At the same time, compound 4H-[1,2,3]thiadiazolo[4,5-b]indole possesses weak antibacterial activity with an IC50 value of 34.1 � 1.0 and MIC > 100.Molecular docking performed on the compound 4H-[1,2,3]thiadiazolo [4,5-b]indole showed a high affinity with binding energy À 6.0 and 5.7 kcal mol-1 and formed key interactions with the active site of transferase enzyme (6AEF) and integrin protein (3FCU).