Periodic nonuniform sampling of second order (PNS2) involves two periodic sequences with the same period. This sampling scheme has been shown to remove aliasing. Moreover, under particular conditions on their spectral band (or spectral support), exact reconstruction of functions can be derived from their PNS2. This paper more generally deals with the best mean-square interpolation for stationary processes with any known power spectrum, from PNS2 and, possibly, with aliasing. We show that the best estimation is based upon particular linear filters, which depend on the gap between both sampling sequences. The mean-time error also depends on this gap. The errorless interpolation is a particular case. It requires the knowledge of the spectral support rather than the power-spectrum values.