Abstract: The thermal-lens apparatus described previously (cf. Dovichi and Harris, Anal. Abstr., 1981, 41, 2J111) was used in conjunction with a microcomputer for real-time data processing. A 1-cm fused-silica flow-cell (1 mm deep) was used in which the carrier stream flowed vertically upwards, thereby minimizing problems due to convection. In the determination of Fe with 1,10-phenanthroline in aqueous methanol (1:1), the limit of detection was 37 pg in a 100 µL sample, while in the determination of azulene and C. I. Solvent Green 3 in CCl4 solution, respective absorbance detection limits of 8.5 x 10^-7 and 14 x 10^-7 were possible. The use of the flow injection procedure was found to minimize problems of photochemical instability frequently encountered in static thermal-lens measurements.