Abstract: Flow injection analysis (FIA) was combined with photochemically induced fluorescence (PIF) detection for the determination of four aminophenothiazines, including ethopropazine, trifluoperazine, levomepromazine and thioproperazine. The working analytical parameters (flow-rate, injected volume, photoreactor length) were optimized. Linear calibration curves were obtained over about two orders of magnitude, with relative standard deviations within the range 1.2-4.5%. Limits of detection and quantification were, respectively, between 60-90 and 200-400 ng.mL-1, according to the compound. The FIA-PIF method was applied to the determination of aminophenothiazines in urine samples and pharmaceutical preparations. Mean recoveries ranged from 87 to 118%, according to the compound. 33 References