In this study, we propose a method to reconstruct photoplethysmogram (PPG) waveforms from other stealthily recorded physiological signals. The proposed method focuses on the frequency characteristics between two physiological signals and reconstructs the target PPG waveform using a regression model. We investigate the feasibility of the proposed method to reconstruct target PPG signals from respiratory (RSP) and PPG signals recorded at non-genuine measurement sites using the two datasets of physiological signals. The results indicate that the proposed method achieves similarities between the target PPG and reconstructed PPG signals with correlation coefficients more than 0.860.