Cement stabilization is one of the most common techniques for stabilizing recycled road base material, and offers a longer pavement life. With the cement effect, the increase in stiffness of the stabilized layer would provide better load transfer to the pavement foundation. The recycling method provides an environmental friendly option as the existing road base materials will not be removed. This paper presents a case study at a trial section along the North-South Expressway in Malaysia, where the Falling Weight Deflectometer (FWD) was adopted to determine the in situ stiffness of the cement stabilized road base material. The FWD would assess the compressive strength and the material stiffness of the cement stabilized layer. The improvement in the stiffness of the stabilized base layer was monitored, and samples were tested during the trial. FWD was found to be useful for the structural assessment of the cement stabilized base layer prior to the placement of asphalt layers. Results from the FWD were also used to verify the assumed design parameters for the pavement. Using the FWD, an empirical relationship between the deflection and the stiffness modulus of the pavement foundation is proposed in this paper.