Despite prenol emerging as a next‐generation biofuel, some questions about its mechanism still need to be adequately proposed to rationalize its consumption and evaluate its efficiency in spark‐ignition (SI) engines. Here, we present new insights into the reaction mechanism of prenol (3‐methyl‐2‐buten‐1‐ol) with OH radicals as a function of temperature and pressure. We have determined that the different temperature and pressure conditions control the preferred products. At combustion temperatures and low pressures, OH‐addition adducts are suppressed, increasing the formation of α and δ allylic radicals responsible for the auto‐ignition. The temperature and pressure conditions can control the reaction products/adducts of the prenol oxidation by OH radicals. Low temperatures and high pressures promote the OH‐addition adducts. High temperatures and low pressures suppress these adducts and promote the formation of allylic radicals.