OBJECTIVE: Use of a wheat growth bio assay after 7 days in research on homeopathic dilutions of gibberellic acid. METHODS: Grains of winter wheat (Triticum aestivum, Capo variety) were observed under the influence of extremely diluted gibberellic acid (10(-30)) prepared by stepwise dilution and agitation according to a protocol derived from homeopathy (30×). Analogously prepared water was used for control. In a two centre study, 3 experiments with a total of 4880 grains were performed. RESULTS: Data were found to be rather homogeneous within the control group as well as within the verum group in general. Germination rates were around 95%, with no significant difference between verum and control group (p>0.05). Mean stalk lengths (mm) were 40.63±20.96 for the verum and 44.33±21.11 for the control group (mean±S.D.) at grain level (N=2440 per group) and ±5.33 and ±5.89, respectively at dish level (122 cohorts of 20 grains per treatment group). In other words, verum stalk length (91.65%) was 8.35% smaller than control stalk length (100%). This difference is statistically highly significant (p<0.001) and was found by both researchers involved independently. CONCLUSION: These results suggest that there was an influence of gibberellic acid 30× on wheat seedling development, i.e. the wheat growth bio assay can be a useful tool for further experiments on homeopathic dilutions of gibberellic acid.