In the crystalline 1:1 molecular complex of triphenylmethanol (TPMeOH) and triphenylphosphine oxide (TPPO), C(19)H(16)O. C(18)H(15)OP, molecular dimers are formed which are linked by O-H. O=P hydrogen bonds. The dimers are aligned by sixfold phenyl embraces to form columns. The structure is disordered with half a dimer per asymmetric crystal unit, i.e. with only one molecular site which is half-occupied by both TPMeOH and TPPO.