Hi, if it should be "lines" so you can do that xy.lm <- lm(y~x) lines(x, xy.lm$coeff[1] + x*xy.lm$coeff[2], col="blue", lwd=3) Regards ep -- View this message in context: http://r.789695.n4.nabble.com/add-a-linear-regression-line-to-the-plot-tp3215455p3216099.html Sent from the R help mailing list archive at Nabble.com.