Quaternary ammonium salts have wide application as surfactants, antimicrobial agents with pronounced antioxidant activity, act as antidotes, acetylcholinesterase inhibitors, therapeutics etc. In order to investigate the biological potential, two new series of quaternary ammonium salts bearing different heterocyclic compounds: quinuclidin-3-ol and pyridinium4-aldoxime containing tertiary nitrogen atom in their structure have been synthesized. Quinuclidin-3-ol is a bicyclic aliphatic compound with a nitrogen-bridged linkage, and pyridinium-4-aldoxime is an aromatic planar compound. For their quaternization, alkyl chains with different lengths of the hydrocarbon chain (3, 4, 6 and 8C atoms) were used. The hydrocarbon chains were mono- or disubstituted with bromine which is a good leaving group in the nucleophilic substitution of tertiary amines of corresponding heterocyclic compounds. For the synthesis of quinuclidin-3-ol quaternary salts, alkyl chains that were used are: 1bromopropane, 1-bromobutane, 1-bromohexane, 1-bromoctane and 1,3-dibromopropane and for the synthesis of quaternary salts of pyridinium-4-aldoxime: 1,3 dibromopropane, 1,4dibromobutane, 1,6-dibromohexane and 1,8-dibromoctane. All the synthesized compounds were obtained as solids in good yields. Thin layer chromatography and melting point confirmed the identity and purity of newly synthetized compounds.