This article reports evidence that a verbal association is symmetrical if its units are equally available. An item's availability was increased by having S produce it from memory. By the PA method S learned pairs of disyllables, which together formed an associative structure. The stimuli of some pairs were responses in other pairs; these stimuli thus became available. S was then asked for 2 free associations to every disyllabic. 4 conclusions were drawn from the response hierarchies: (a) Available items occurred more often as responses in all hierarchies, (b) A backward association occurred as readily as a learned forward association if the PA stimulus was available, (c) Associations occurred between items that had shared a common associate, even though these items had not coappeared. Such associations, however, only manifested themselves when their response was available, (d) The data did not support a simple principle of mediation as an explanatory concept.