Couroupita guianensis (C. guianensis) Aubl. is an important medicinal plant utilized from ancient time for the treatment of various diseases. Different parts of the plant including root, stem, leaves, flower and fruit are exploited for their anti-inflammatory, anti-oxidative, anti-cardiac, antidiabetic, antibacterial and anticancer activities. In the present study, anther extract was utilized for cost effective and rapid synthesis of anther silver nanoparticles (A-AgNPs). The synthesis of silver nanoparticles was initially confirmed by surface plasmon resonance vibration with ultraviolet-visible spectroscopy (UV-Vis). Fourier-transform infrared spectroscopy (FTIR) analysis supported the capping and stability of A-AgNPs due to the presence of biomolecules in the extract. High-resolution transmission electron microscopy (HR-TEM) and scanning electron microscopy (SEM) analysis showed the synthesis of spherical, monodispersed and aggregated A-AgNPs and energy dispersive X-ray analysis (EDXA) confirmed the presence of silver. The efficacy of the A-AgNPs was screened against human bacterial pathogens (gram positive and gram negative), showing significant growth inhibition and biofilm formation. The results demonstrated that anthers of C. guianensis is a potent biosource for green synthesis of stable and reproducible silver nanoparticles and can be utilized as an alternative, cost-effective and potent alternative to antibiotics.