Background: Fluoroquinolones (FQs) are one of the most prescribed classes of antibiotics in North America. There have been a number of cases reports linkingn FQs with secondary pseudotumor cerebri syndrome (PTCS) but data from large epidemiological studies are lacking. Methods: We conducted a case-control study of people 15-60 years of age from the LifeLink Database (IMS, USA). Cases had the first international classification for disease 9th edition clinical modification (ICD-9 CM) code for benign intracranial hypertension (BIH) as well as having received a procedure code for an MRI or CT scan and a lumbar puncture within 15 days or 30 days of receiving the BIH code. For each case, ten controls were selected and matched to the cases by age, gender and calendar time. Results: From a cohort of 6,110,723 people, there were 339 cases of PTCS and 3,390 corresponding controls. In the primary analysis, the adjusted rate ratio (RR) for current users for fluoroquinolones for both the 15 day and 30 day definitions were 5.67 (95% CI:2.72-11.83) and 4.15 (95% CI:2.29-7.50) respectively. Conclusions: Our study suggests an increase in the risk of PTCS with current users of fluoroquinolones. Patients who experience symptoms of raised intracranial pressure including headaches and double vision when on FQs should seek medical attention.