Nanoparticles (NP) are used effectively in many fields. In addition to physical and chemical methods in its synthesis, there are also biological methods that are quite outstanding today. In this method, which is also called green synthesis, the green synthesis method was preferred in the study, since components that do not harm humans and the environment are used. Aqueous extracts of the leaf and spice of basil (Ocimum basilicum L.) were used at different concentrations. The sizes of NPs obtained from repeated studies were examined. As a result of DLS size measurement, silver nanoparticles (AgNP) with a size of 138.3 nm from the leaf and 188.6 nm from the spice were obtained. When the anticancer activity of various AgNPs synthesized during the study was examined on A549 cells, it was seen that the AgNPs of basil leaves, which were used without waiting, with a size of 138.3 nm, in the concentration range of 2.5 and 3.25 mg mL-1, provided the most anticancer effect.