Novel omega-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl derivatives 1-6 containing 4-, 5- and/or 6-arylsubstituted pyrid-2(1H)-one moiety were synthesized. All the new compounds were examined in vitro to assess their 5-HT1A and 5-HT2A receptor affinities. Compounds 3 and 4 with a 5- or a 6-phenylsubstituted pyridone ring demonstrated high 5-HT1A receptor affinity (Ki = 17 and 38 nM, respectively) and were tested in behavioral functional models. Derivative 3 can be regarded as a weak 5-HT1A postsynaptic antagonist, whereas 4 showed features of a weak partial agonist of 5-HT1A receptors (an agonist of pre- and an antagonist of postsynaptic ones). Binding affinities and in vivo results were discussed in comparison with those for the previously described tetramethylene analogs. The obtained results showed that the shortening of the aliphatic chain to two methylene groups exposed the intrinsic activity of the ligand 4 at 5-HT1A receptor sites.