The present study aimed to examine the extent of utilizing Open Educational Resources (OER) in mathematics instruction for the intermediate school in Riyadh, Saudi Arabia. It also aimed at identifying the benefits, the challenges, and the opportunities of applying OER in the educational process. For achieving the study objectives, the descriptive analytical approach was adopted. The study population comprised all the teachers of the intermediate school in Riyadh. A questionnaire was prepared and applied to a randomly selected sample of (113) teachers of the intermediate school. In the light of the findings, a set of recommendations and further studies were formulated.