Phosphocholine 2, 6-xylyl ether bromide [PPP-trimethyl-2-(2, 6-xylyloxy)ethylphosphonium bromide], has been synthesized by reacting 2-(2, 6-xylyloxy)ethyl bromide with a solution of trimethyl-phosphine in phenol, but ethylenebis(trimethylphosphonium bromide), 1, 2-di(2, 6-xylyloxy)ethane and 2, 6-xylenol were the only reaction products identified when ether was used as solvent. The 2JPH and 3JPH coupling constants for these phosphonium salts have been determined. Although the phosphocholine xylyl ether blocks the Finkleman preparation in concentrations of 2–3 × 10−5 g/ml, this blockade does not have all the characteristics of the adrenergic neuron blockade produced by xylocholine.