Today, nanotechnology has led to the introduction of a large number of nano products, of which silver nanoparticles are one of the most common nanomaterials. Silver nanoparticles are more widely used than other types of metal nanoparticles due to their physical and chemical properties and have distinctive features and wide applications, especially in agriculture, which affect the growth and quality of plants. In this study, the effect of different concentrations of silver nanoparticles on some physiological and morphological indicators of geranium plant was investigated. The experiment was conducted in a completely randomized block design with 3 replications by applying silver nanoparticles treatment at four concentrations (zero, 10, 20 and 30 mg/L). The results showed that various growth indices including leaf blade width, plant height, stem diameter, flower diameter, catalase enzyme activity, flowering time, and petal anthocyanin content, leaf chlorophyll, and nitrogen and potassium elements increased significantly under the influence of silver nanoparticles. The highest and best levels of these indices were observed at concentrations of 20 and 10 mg/L of silver nanoparticles. Based on the results of this study, the use of silver nanoparticles as a suitable stimulus for improving growth indices and physiological traits of plants is suggested.