For original paper see N. J. Florous et al., ibid., vol.18, no.15, p.1663 (2006). Florous et al. presented calculations of thermal sensitivity of photonic crystal fibers (PCFs) with elliptical holes. In this Comment Antkowiak and Kotynski compare these results with those obtained by them previously. They also include improved calculations of the thermooptics effect contribution to the polarimetric sensitivity of PCF and, on this basis, present a critical analysis of the calculations given in both papers