The title compounds, 4-(2-naphthyloxymethylcarbonyl)morpholine, C(16)H(17)NO(3), (I), and 4-methyl-1-(2-naphthyloxymethylcarbonyl)piperazine, C(17)H(20)N(2)O(2), (II), are potential antiamnesics. The morpholine ring in (I) and the piperazine ring in (II) adopt chair conformations. In (I), the molecules are linked by weak intermolecular C-H.O interactions into chains that have a graph-set motif of C(10), while in (II), the molecules are linked by weak intermolecular C-H.O interactions that generate two C(7) graph-set motifs. The dihedral angle between the naphthalene moiety and the best plane through the morpholine ring is 20.62 (4) degrees in (I), while the naphthalene moiety is oriented nearly perpendicular to the mean plane of the piperazine ring in (II).