The etiologies of well-known cavernous sinus syndrome are many. It is necessary to identify clinical and radiologic findings of various cavernous sinus syndromes to avoid major mistakes in treatment. As an example, pitfalls in the diagnosis of Tolosa-Hunt syndrome (THS) are not rare. In this study, we report a case series of THS and review and discuss the mistakes in the diagnosis of cavernous sinus syndromes. This study was conducted during a 10-year-period between 1997 and 2007. There were 10 patients (6 males, 4 females) in this series. Patients were included in this series only if they fulfilled the International Headache Society criteria for Tolosa-Hunt syndrome. Follow-up duration of the patients ranged from 6 months to 9 years (mean=3.8 y). Age of the patients (n=10) ranged from 23 to 70 years (mean=44 y). According to magnetic resonance scans, the lesion was located in the cavernous sinus only in 6 cases; in the orbit only in 1 case; and in cavernous sinus as well as superior orbital fissure and ipsilateral orbit in 1 case; and in both the cavernous sinus and ipsilateral superior orbital fissure in 1 patient. In 1 patient, there was no magnetic resonance imaging abnormality. Nine out of 10 patients completely recovered after steroid therapy. In conclusion, good knowledge of clinical presentation of orbital pseudotumor and THS is very helpful in clinical decision-making in a patient with cavernous sinus syndrome.