Compensation techniques for fiber attenuation and chromatic dispersion are opening up the way for a bit-rate upgrade to 10 Gb/s of the terrestrial fiber networks. The high polarization mode dispersion of many of the already installed optical fibers poses a serious challenge, however, to a singlechannel implementation of this upgrade. In this paper, we propose an assessment of the impairments caused by firstand second-order polarization dispersion in nonzero chromatic dispersion fibers. We first develop a pulse shape analysis so as to evaluate the induced distorsions. We then establish a general formula for the transmission penalties, revealing that the effect of second-order polarization dispersion builds up with chromatic dispersion and can induce a severe degradation of the transmission performance. Finally, we deduce from a statistical analysis that the mean penalty is solely related to chromatic dispersion and first-order polarization dispersion, while the standard deviation of the penalties can increase severalfold in the presence of chromatic dispersion owing to second-order polarization dispersion.