Background: The pulses palpated on the left and right radial arteries are said to have diagnostic significances in traditional Chinese medicine. This study investigated whether the pulse waveforms recorded at bilateral index fingers are differentiable by comparing the power spectra of pulse waveform between bilateral pulses and between non-pregnant and late pregnant women. Methods: Forty seven healthy non-pregnant women and 23 women in the third trimester of pregnancy were included in this study. A train of pulse waveform recorded via a pulse oximeter was acquired and transformed into power spectrum by means of fast Fourier transformation. The power spectra of bilateral pulse waveform were compared with each other in non-pregnant and late pregnant women. Results: The total power of pulse (TPp) of right pulse and normalized powers of the 5th, 6th, 7th, 8th harmonics (nP5~nP8) of bilateral pulses in late pregnant women were significantly smaller than their counterparts in nonpregnant women, whereas the normalized powers of the 2nd harmonics (nP2) of left and right pulses in late pregnant women were significantly greater than their counterparts in non-pregnant women. The nP4 and nP5 of left pulse were significantly smaller than those of right pulse in the non-pregnant women, but this left-right asymmetry in nP4 and nP5 disappeared in late pregnant women. Conclusion: Pregnancy can lead to a decrease in the TPp of right pulse, and nP5~nP8 of bilateral pulses, but an increase in nP2 of bilateral pulses. The nP4 and nP5 of left pulse are significantly smaller than those of the right pulse in non-pregnant women, but this left-right asymmetry in nP4 and nP5 disappears during late pregnancy. The changes in bilateral pulse waveform might be associated with the aorto-caval compression during late pregnancy.