Hi, It seems that write.csv doesn't support append now. Use write.table() write.table(dataF, file = outputFilePath, append=T,col.names =F) Regards, Wu ----- A R learner. -- View this message in context: http://r.789695.n4.nabble.com/Append-to-csv-without-header-tp2322115p2322172.html Sent from the R help mailing list archive at Nabble.com.