To examine the anticancer effects of S-allyl-L-cysteine (SAC) in human bladder cancer cells and to identify possible molecular mechanisms, bladder cancer cell lines (HTB5, HTB9, JON, UMUC14, T24, and cisplatin resistant-T24R2) were incubated with SAC, and cell proliferation was measured using the Cell Counting Kit-8 assay and clonogenic assay.