The prevalence of oral squamous cell carcinoma (OSCC) has increased in the last 2 decades. For the treatment of this disease, various herbal anticancer agents have been introduced. In this study, for the first time, we analyzed the apoptotic and cytotoxic effects of herbal plants, including Anacyclus pyrethrum, Terminalia chebula, and Brassica nigra, in KB cancer cell lines. For analyzing the cytotoxic effects of ethanol extracts, MTT reduction assay was performed in the KB cells. Moreover, the apoptosis-inducing effect of plants on KB cells was assessed using TUNEL and DNA fragmentation assays. The results showed that Anacyclus pyrethrum and Terminalia chebula extracts significantly inhibited cell viability. TUNEL and DNA fragmentation assays showed that the main mechanism of cell death was apoptosis induction by Anacyclus pyrethrum and Terminalia chebula extracts. Our results suggest that these ethanol extracts may contain bioactive constituents, which can be helpful in OSCC treatment.