We report on the polarization-mode dispersion (PMD)-induced crosstalk in the presence of polarization scrambling. When the polarization scrambling was used, PMD could generate unwanted intensity modulation and degrade receiver sensitivity. The results showed that, even when the differential group delay was only 10 ps, the bit-synchronous polarization scrambling could increase the power penalty up to 1 dB for 10-Gb/s nonreturn-to-zero signal.