The synthesis and radioligand binding assays of a group of muscarinic ligands related to oxotremorine are reported. The new compounds displayed binding affinities comparable to those of the parent molecule with the exception of the trimethylammonium salt 6, which behaved as a full muscarinic agonist and showed a pronounced selectivity for M 2 versus M1 muscarinic receptor subtypes. © 1997 Elsevier Science Ltd.