The efficacy of biologically synthesized silver nanoparticles (AgNPs) was evaluated for their potential to improve the postharvest quality of rose cut flowers cv. ‘First Red’. AgNPs were applied as pulse treatment at 25, 50 and 100 mg L−1 for 24 h. Control flowers were pulsed in distilled water for the same period of time. The treated and untreated flowers were then transferred to distilled water for vase life evaluation. All levels of AgNPs significantly prolonged the vase life compared with the control. The microbial growth was suppressed in vase solution, while relative fresh weight (RFW), relative water content (RWC) and chlorophyll content as well as membrane stability index (MSI) were maintained as a result of using AgNPs. In addition, stomatal conductance, ethylene production and malondialdehyde (MDA) were decreased in response to AgNPs application. H2O2 production was decreased while antioxidant enzyme activities (CAT, SOD and POX) were increased in AgNPs treated flowers relative to the control. Among AgNPs treatments, the most effective level was 50 mg L−1. The results suggest that the biologically synthesized AgNPs could be used for improving the postharvest quality of cut roses as a promising eco-friendly, non toxic and novel alternative source to chemical and physical AgNPs sources or common chemicals used in preservative solutions in rose flowers.