The presence of frontal cells poses unique challenges when using endoscopic approaches. This study describes the use of a balloon dilation system as an aid for functional endoscopic sinus surgery (FESS) to access the frontal sinus in cases that would traditionally require open approaches. We present a case series of four patients with chronic rhinosinusitis refractive to medical management who underwent FESS with the aid of a balloon dilation system at a tertiary referral center. All patients had variant forms of frontal sinus anatomy. Surgical techniques will be described and use of the balloon system will be reviewed. All patients (aged 13-68 years) successfully underwent fontal sinusotomies with the assistance of a balloon dilation system, which was used in a variety of ways: to dilate the narrow infundibulum of a high intersinus septal cell, to remove an anteriorly located type III frontal sinus cell, to expand the natural frontal ostium in the presence of excessive agger nasi pneumatization, and to remove a type IV frontal sinus cell. All patients were spared an osteoplastic flap or trephination, and there were no intraoperative complications. No postoperative bleeding, infection, or cerebral spinal fluid leaks were reported. Balloon dilation in combination with standard frontal sinus dissection techniques may be beneficial for a select group of patients with complex frontal anatomy. In this series of patients, the balloon dilation system was used as a tool during FESS and eliminated the need for open approaches.