The antimicrobial activity of novel compounds is tested by determining the minimum inhibitory concentration of the agent in question and investigating a few other parameters, including the type of antimicrobial action the drug exhibits. The aim of this study was to determine the type of antimicrobial action of the compounds synthesized from the substituted benzaminoindoles. The strain of Staphylococcus aureus АТСС 6538-Р was briefly exposed to the compounds with laboratory codes 5D, 7D, HD, and S3. Bacterial growth was evaluated macroscopically under transmitted light. Additionally, photoelectric colorimetry was applied to monitor changes in the optical density of the culture medium. The minimum inhibitory concentrations of the studied compounds delayed bacterial growth for 2–3 days and had a bacteriostatic effect on S. aureus.