x and y axis labels changing in ggplo2: p <- ggplot(d03, aes(x=cs,y=taille)) + geom_hline(data=temp.df) + geom_boxplot() + facet_grid(.~sexe) I had a similar question not too long ago. Try: p + scale_x_discrete("new label x") + scale_y_continuous("new label y") best wishes ido