Postoperative urinary retention, in the absence of primary organic disturbances in the urinary bladder, may ensue as a sequel to surgical operations notwithstanding a full bladder, normal kidney function, and the desire to void. To counteract this condition, new cholinergic drugs have been developed that increase the vesical activity and mimic the effects of parasympathetic stimulation.1Clinically, they have been shown to produce increased bladder activity and thus aid in the promotion of normal urinary function.2In the following report the effectiveness of two new members of this cholinergic group, benzpyrinium (Stigmonene) bromide [1-benzyl-3-(dimethylcarbamyloxy) pyridinium bromide] and 1,2-xylylene-bis[1-(3-dimethylcarbamyloxy)-pyridinium bromide], a related experimental cholinergic compound coded W341, are compared and their efficacy evaluated in the treatment of established postoperative urinary retention. The chemical configuration of the two cholinergic compounds are given in figure 1.That benzpyrinium bromide acts as an inhibitor of cholinesterase,3is less toxic than physostigmine