This article describes how the inclusion and positioning of a lateral hydroxy group influences the thermal stability of a chiral smectic C phase. An off-central position of the hydroxy group in the aromatic core has the effect of enhancing the thermal stability of the chiral smectic C phase, whereas a central position of the hydroxy group destabilizes it to the extent that there is no evidence for the phase being present. The results indicate that a hydroxy grouportho- to an ester function gives intra- rather than inter-molecular hydrogen bonding. The effects seen with lateral and terminal hydroxy groups are compared with those for analogous fluoro-substituted systems.