We perform the analysis of the impact of noise in the phase- shifting interferometry. The effect of the multiplicative noise is equivalent to the (pixel-variable) modulating intensity error, while the additive noise has the two-fold consequences, equivalent to the (pixel-variable) phase-shift error and the modulating intensity error. We evaluate the relative importance of the errors in the background intensity, the modulating intensity, and the phase-shift on the accuracy of the phase recovery. The phase reconstruction process is more sensitive to the phase displacement error than to the intensity error. Finally, we show that the phase reconstruction process is more sensitive to the additive noise than to the multiplicative noise.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.