We report a simple and high-yielding two-step procedure for the preparation of 8-arylated guanosine mono- and triphosphates (8-aryl GXPs). The key step of our synthesis is the Suzuki–Miyaura coupling of unprotected 8-bromo GMP and 8-bromo GTP with various arylboronic acids in aqueous solution. The 8-bromoguanosine 5′-phosphates required as cross-coupling substrates were prepared from 8-bromoguanosine via an optimised Yoshikawa procedure.