Heamatang (HMT) is a classic medicinal formula used in traditional Chinese and Korean medicine; it contains seven distinct components, mainly of herbal origin. HMT is used as an antiaging remedy, treating urinary disorders and increasing energy and vitality. However, the therapeutic applications of this formula have not been evaluated with evidence-based science. Therefore, we assessed HMT through various in vitro methods, including cell viability assay, fluorescence-activated cell sorting assay (FACS), Western blotting, migration assay, three-dimensional (3D) cell culture, siRNA-mediated PAK-1 knockdown, and crystal violet assays. HMT decreased PAK-1 expression in PC-3 cells and inhibited cell viability, growth, and motility. The inhibition of cell motility by HMT was correlated with PAK-1-mediated inhibition of Lim domain kinase (LIMK) and cofilin. HMT induced G1 arrest and apoptosis through the transcriptional regulation of cell cycle regulatory proteins and apoptosis-related proteins (increase in c-cas3 and inhibition of PARP and BCL-2). Moreover, HMT suppressed PAK-1 expression, leading to the inhibition of AKT activities. Finally, we showed that decursin was the active ingredient involved in the inhibitory effect of HMT on PAK-1. Our findings demonstrated that HMT exerts its anticancer influence through the inhibition of PAK-1. The HMT formula could be applied in various fields, including functional health food and pharmaceutical development.