The aim of this study was to green synthesised silver nanoparticles (AgNPs) using Centella asiatica leaf extract and investigate the cytotoxic and apoptosis-inducing effects of these nanoparticles in MCF-7 breast cancer cell line. The characteristics and morphology of the green synthesised AgNPs were evaluated using transmission electron microscopy, scanning electron microscopy, UV-visible spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The MTT assay was used to investigate the anti-proliferative activity of biosynthesised nanoparticles in MCF-7 cells. Apoptosis test was performed using flow cytometry and expression of caspase 3 and 9 genes. The spherical AgNPs with an average size of 19.17 nm were synthesised. The results showed that biosynthesised AgNPs exhibited cytotoxicity, anti-cancer, apoptosis induction, and increased expression of genes encoding for caspases 3 and 9 in MCF-7 cancer cells in a concentration- and time-dependent manner. It seems that green synthesised AgNPs have potential uses for pharmaceutical industries.