Green synthesis of silver nanoparticles (AgNPs) was developed by treating Ag+ with Alcea rosea flower extract. AgNO3 concentration, flower extract quantity, and reaction temperature were found to be significant factors in the bioreduction reaction. Synthesized AgNPs were almost spherical in shape with an average diameter of 7.2 nm. Fourier transform infrared spectroscopy (FTIR) analysis revealed that oxygen-bearing functional groups in the A. rosea flower extract are responsible for reduction of Ag+. The minimum inhibitory concentration (MIC) of AgNPs against a Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria was determined to be 37.5 ?g/ml.