Abstract
Radial O/H abundance gradients derived from H II regions, hot stars and planetary nebulae are combined with [Fe/H] gradients from open cluster stars in order to derive an independent [O/Fe]-[Fe/H] relation for the Galactic disk. A comparison of the obtained relation with recent observational data and theoretical models suggests that the [O/Fe] ratio is not higher than [O/Fe] =~ 0.4, at least within the metallicity range of the considered samples.
