Protein N-myristoylation enables localization to membranes and helps maintain protein conformation and function. N-myristoyltransferases (NMT) catalyze co- or post-translational myristoylation of Src family kinases and other oncogenic proteins, thereby regulating their function. In this study, we provide genetic and pharmacological evidence that inhibiting the N-myristoyltransferase NMT1 suppresses cell cycle progression, proliferation and malignant growth of prostate cancer cells. Loss of myristoylation abolished the tumorigenic potential of Src and its synergy with androgen receptor in mediating tumor invasion. We identified the myristoyl-CoA analog B13 as a small molecule inhibitor of NMT1 enzymatic activity. B13 exposure blocked Src myristoylation and Src localizaiton to the cytoplasmic membrane, attenuating Src-mediated oncogenic signaling. B13 exerted its antiinvasive and antitumor effects against prostate cancer cells with minimal toxic side-effects in vivo. Structural optimization based on structure-activity relationships enabled the chemical synthesis of LCL204 with enhanced inhibitory potency against NMT1. Collectively, our results offer a preclincal proof of concept for the use of protein myristoylation inhibitors as a strategy to block prostate cancer progression.