The synthesis and mesophase characterization of some monosubstituted ferrocene-containing liquid crystals were reported. For a better understanding of the thermal behavior, the LC properties were compared with a series of pattern compounds, possessing similar structures, but without the ferrocenyl unit. The introduction of the ferrocenyl unit in the rigid core induced monotropic or enantiotropic behavior, depending upon the number of carbonyl groups in the structure. Monotropic behavior is a little surprising, since the presence of the bulky ferrocenyl unit is expected to inhibit the ordering process in the solid state (crystallization). The observed behavior is rationalized by the change of the dipole moment in the rigid core, when either one or two ester groups are present.