We have investigated the sustainable synthesis of silver nanoparticles (AgNPs) using blueberry (Vaccinium corymbosum L.) ethanolic extract from the point of view of the intervening metabolites. An extensive NMR metabolomic approach based on nuclear magnetic resonance (NMR) spectroscopy and headspace-solid phase microextraction (HS-SPME) followed by gas chromatography/quadrupole-mass spectrometry (GC-qMS) has been directed in order to ascertain for the first time the involved bioactive molecules as those responsible for the synthesis of AgNPs. The green process was monitored through UV-vis spectrophotometry, and a plethora of techniques such as EDX, XRD, XPS, TEM, SEM, and DLS were used to confirm the formation of the AgNPs. The successful synthesis was indirectly proven by their antibacterial activity against Gram-positive Streptococcus pyogenes and Gram-negative bacteria Salmonella typhi.