The present work describes a rapid and easy way to study foreign gene expression in wheat through microparticle bombardment. Transient expression of the GUS reporter gene was evaluated in different tissues of the cultivar Buck Omb?. Transformation was carried out employing a helium gun microparticle accelerator and several plasmids. Embryogenic calli, immature embryos and immature inflorescences showed a higher number of transformed cells per Petri dish. Basal leaf segments were the least efficient. When vectors were tested in scutellar tissue of immature embryos, the maize ubiquitin promoter (Ubi1) produced the highest level of transient GUS expression, followed by the alcohol dehydrogenase promoter of maize plus its first intron (Adh1 Adh intron 1) and the sunflower ubiquitin promoter. The CaMV35S promoter was the least effective. These results were in agreement with previous reports carried out in cell suspensions or embryogenic calli and indicate that wheat immature embryos and immature inflorescences are suitable for rapid test of promoter sequences or transformation conditions. Moreover, efficient transformation of these explants could help in the stable transformation of agro nomically important genotypes.