A versatile method for the synthesis of new oxindoles was developed by the reaction between substituted isatins and 5-aminopyrazoles. The reaction was carried out at room temperature in ethanol using p -toluenesulfonic acid as the catalyst. The products were obtained with acceptable to excellent yields (44–96%). Structures of the new compounds were unambiguously established by spectroscopic and analytical techniques. The antibacterial activity was determined by microdilution assays. Compounds 3b , 3e, and 3g showed antistaphylococcal activity, particularly compound 3e displayed a potent activity against the vancomycin intermediate Staphylococcus aureus (VISA). Compounds 3i , 3j, and 3o inhibited Neisseria gonorrhoeae growth.