Organosulfur compound's functionality constitutes an essential class of therapeutic agents in current medicinal chemistry. Especially sulfonamides called sulfa drugs were performed as both chemotherapeutic agents and useful antibacterial derivatives developed for medicine. The sulfamides in the same family with the sulfonamides have similar biological activities. In our research, it was studied with some 3-imino-4-substituted-1, 2, 5-thiadiazolidine 1,1-dioxides (ISTDs-4a-d, four samples) that are five-membered cyclosulfamides. These compounds were previously synthesized and structurally characterized. The goals of this study are to investigate minimum inhibition concentration (MIC) values and antibacterial effects of these ISTDs compounds on Bacillus subtilis NRRL B-209 T , Escherichia coli ATCC®25922 T , Micrococcus luteus NRRL B-1018 T , Nocardia abscessus DSM 44432 T , Nocardia cyriacigeorgica DSMZ 44484 T , Pseudomonas aeruginosa NRRL B-2679 T Staphylococcus aureus ATCC®6538 T , Streptomyces murinus ISP 5091 T .