Forty-eight patients with partial seizures were analysed during treatment with 1200 mg/d or more of carbamazepine (CBZ). Thirty-three were on monotherapy and fifteen on polytherapy. The other drugs were kept unchanged in the patients on polytherapy. The dose of CBZ was increased if no control was observed and the patient had no side effects. The doses used ranged between 1200 and 1900 mg/day (1200 mg/day, n = 18; 1300 mg/day, n = 1; 1400 mg/day, n = 7; 1600 mg/day, n = 9; 1700 mg/day, n = 4; 1800 mg/day, n = 8; 1900 mg/day, n = 1). Anticonvulsant plasma levels were taken to confirm patient compliance. The average plasma level was 9.6 ug/mL. The period of follow up varied from 3 to 96 months (M = 25.6). Seizure's control was observed in 7 (14.48%) patients taking 1200 mg/day and in 2 (4.16%) patients taking 1400 mg/day of CBZ. Thirty-nine patients did not show any control (81.21%). Ten patients (20.81%) had signs of intoxication. When patients have no improvement with 1400 mg/day, it is difficult to obtain any control despite the use of higher doses of CBZ, which frequently expose the patient to significant side effects.