Microbe mediated synthesis of silver nanoparticles (AgNPs) constitutes a reliable, eco-friendly approach ameliorating green-chemistry principles. In this study, stable silver nanoparticles were synthesized by exposing aqueous silver ions to extracellular exudates of B. subtilis A1 under optimized laboratory conditions. The synthesized nanoparticles were characterized by spectroscopic and microscopic techniques. The plasmon resonance and diffraction patterns revealed the typical characteristics of silver with an average size of ~35.42nm and spherical in shape. Larvicidal assay performed using AgNPs showed significant results toward fourth instars of Anopheles stephensi and Aedes aegypti larvae. The results suggest that the B. subtilis A1 mediated synthesis of AgNPs possess excellent antimicrobial and larvicidal properties that may represent promising bio-control agent with improved biomedical applications.