We sought to develop a simple synthetic procedure for azophosphines that would be tolerant to bulky groups on the phosphorus centre. Azophosphonium cations, [Ar-N=N-PR3] + , have recently been synthesised and are readily accessible by simple addition of a tertiary phosphine (PR3) to an arenediazonium salt. In our hands, the analogous reactivity of a secondary phosphine (HPR2) with arenediazonium cations (for subsequent deprotonation to the neutral azophosphine) led to uncontrolled reactivity and decomposition. Similarly unsuccessful results were observed for direct reactions of phosphide anions ([PR2] -) with diazonium salts, which we postulate is due to singleelectron transfer processes and subsequent decomposition of the neutral diazenyl radical.