Background The intraosseous artery is a branch of the posterior superior alveolar artery that supplies the lateral wall of the maxillary sinus. The present study seeks to analyze the location of the intraosseous artery and its site of termination. Methods Cone beam computed tomography was used to evaluate 200 patients making up 400 maxillary sinuses. The following criteria were measured: (1) the distance of the lower border of the intraosseous artery to the floor of the sinus, (2) the average length of the artery, (3) the diameter of the artery, (4) the site at which the artery terminates at, and (5) the distance of the artery from the first premolar, second premolar, first molar, second molar, and third molar. Results The intraosseous artery was identified in 336 (84.0%) quadrants. The most common site of termination was at the mesial of the second molar (22%), regardless of dental status and right or left quadrant. Its overall mean diameter was 0.91 ± 0.56 mm, with no difference within the dental status. Its overall mean length was 7.40 ± 3.39 mm, with a statistically significant difference between dentate and edentulous quadrants (P < 0.001). Its overall mean distance from the floor was 6.95 ± 6.49 mm, with no difference within the dental status. All parameters showed no difference between right or left quadrants. Conclusions The chances of encountering the intraosseous artery at the premolar area is <21% during a lateral window sinus floor elevation. The most common (22%) site of termination of the intraosseous artery is at the mesial of the second molar. Understanding of the course, location, and termination of the artery enhances the precision of a clinician when it comes to pre‐operative treatment planning.