Even though the chemistry of P₄ has been investigated for many decades, its chemical reactivity towards the simplest electrophile, the proton, is still virtually unknown. The Müller and Riedel group report now for the first time on the successful protonation of P₄ by the Brønsted superacid H[Al(OTeF₅)₄]_(solv). The spectroscopic results are in agreement with an acid-mediated activation of P₄ under protonation of an edge of the P₄-tetrahedron and formation of a three-center two-electron P–H–P bond. These investigations are of fundamental interest as they permit the activation of P₄ with the simplest electrophile as a new prototype reaction for this molecule.