library(ggplot2) # Example data using mtcars a <- aggregate(mpg ~ vs + am , mtcars, function(i) round(mean(i))) p <- ggplot(mtcars, aes(factor(vs), y=mpg, fill=factor(am))) + geom_bar(stat="identity",position="dodge") + geom_text(data = a, aes(label = mpg), position = position_dodge(width=0.9), size=20)