This paper presents several very sensitive fluorimetric-FIA methods for determination of pyridoxal and pyridoxal-5-phosphate based on their oxidation in the presence of cyanide. Calibration curves have been run over the concentration range of 2.5×10−8- 1.0×10−3M (5.0 ppb-203.6 ppm and 6.3 ppb-265.2 ppm, respectively) finding an r.s.d. of 0.3% and a sampling rate of 25 samples. h−1for both species. The presence of NAD is tolerated up to a 336 and 194 fold amount, respectively, for each compound.