This study was conducted in cooperation with a United States pulp and paper company targeting part of the pulp production as raw material for fiber-reinforced cement sheets manufacturing. Virgin kraft pulp of Douglas fir (Pseudotsuga menziesii) and recycled fiber of old corrugated containers were used in making wood fiber-cement flat sheets. The physical and mechanical properties of the sheets were compared with an available commercial product. Results showed that Douglas fir fiber is a potential choice as reinforcement for wood fiber-cement sheets, as this fiber type outperformed the commercial ones for most of the properties studied. The difference in kappa number from 25 to 35 did not have any effect on the properties of Douglas fir sheets. Even recycled old corrugated containers fiber provided sheets with some properties comparable to the commercial product. Scanning electron microscopy analysis showed that a dual mechanism of fiber breakage and pull out occurred at rupture.