Most of the patients with sleep apnea syndrome (SAS) also known as sleep disordered breathing are not diagnosed before undergoing any cardiac interventional procedure. Many of them can safely undergo outpatient procedure under sedation or anesthesia. Few of them with moderate to severe grade of SAS, who are not optimized medically, may create problem and need special consideration. We managed three such cases in cardiac catheterization laboratory; two of them were not diagnosed before. The periprocedural problems we faced in these patients are narrated in this article along with review of literature. Some suggestions for management of such patients undergoing therapeutic cardiac catheterization are also highlighted.