Flow injection analysis methodology is reported for the determination of ranitidine and salbutamol (in pharmaceutical formulations) based on their chemiluminescent reactions with tris(2,2'-bipyridyl)ruthenium(III) and acidic potassium permanganate, respectively. While the log-log calibration function for ranitidine showed significant non linearity, the precision (measured as relative standard deviation) was 1.7% (n=6 1x10 - 5 M) and the detection limit (3σ blank) was 6x10 - 7 M. A linear log-log calibration function was obtained for salbutamol, the precision being 2.7% (n=6; 1x10 - 7 M) with a detection limit (signal to noise ratio=3) of 2.5x10 - 8 M.