The authors specified, briefly, the different subgroups and prevalence of the molecules from the quinolone family: Nalidixic acid (synthesised in 1958), the quinolones of second generation (oxilinic acid, piromidique, pipemidique and flumequine) and the quinolones of third generation (ciprofloxacine, norfloxacine, ofloxacine, perfloxacine). After having mentioned the extent and the importance of using these antibiotics in infections, they stressed the fact that the quinolones are antibiotics which are largely prescribed in clinics and hospitals. The authors reported afterwards the observation of a young female, without any precedent neuropsychiatric disorders having shown a complex clinical state with neurological and psychiatric disturbances during the first day of treatment for a urinary infection with 4 tablets of flumequine 400 mg per day (instead of 3 recommended). Mrs. A. 25 years of age was seen to during the night at The "Consultation Psychiatrique d'Orientation et d'Accueil" (C.P.O.A.). of Sainte-Anne hospital by the resident psychiatric of a General Hospital "after behavioural disturbances". In fact, about 3 hours before and 15 minutes after the third dose of flumequine (2 tablets of 400 mg), this makes the total dose taken over 12 hours is equal to 400 x 4 = 1,600 mg, the patient developed an intense discomfort with blurred vision accompanied by nausea, followed by a state of restlessness and incomprehensible speech. A testimony by relatives revealed that she suffered, shortly afterwards, a generalised fit which affected her 4 limbs with a fixation of her eyes and hypersalivation and convulsions without either swallowing the tongue or involuntary urination.(ABSTRACT TRUNCATED AT 250 WORDS)