A rapid and sensitive chemiluminescence (CL) method was developed for the determination of gibberellic acid. The method is based on the CL reaction of gibberellic acid with Ce (IV) and tris (2,2'-bipyridyl) ruthenium (II). Ru (bipy)₃²⁺. After optimization of the different experimental parameters. a calibration graph was obtained over a concentration range of 0.11 μg/ml - 11.3 μg/ml with minimum detectability of 0.091 μg/ml (S/N=3). The correlation coefficient was 0.992 (n=7) with a relative standard deviation (% R.S.D.) of 1.61%.