Labeling experiments with [3H]palmitic and [3H]myristic acids of African swine fever virus-infected Vero cells have shown that 11 proteins induced during infection are covalently bound to myristic acid and that palmitic acid was not attached to viral proteins. The time course of synthesis of the myristylated polypeptides and the requirements of viral DNA replication indicated that the myristylated proteins, with the exception of a 13-kDa protein, belong to the late class of viral proteins. The myristic moiety was not released by hydroxylamine treatment, suggesting that the fatty acid is bound to the polypeptide chain through an amide linkage. The purification of [3H]myristic acid-labeled extracellular virus particles demonstrated that the myristylated 28- and 13-kDa proteins incorporated into the virion.