I found the answer here: http://www.r-bloggers.com/importexport-data-to-and-from-xlsx-files/ -- View this message in context: http://r.789695.n4.nabble.com/XLSX-Help-Exporting-to-multiple-sheets-in-excel-tp4675767p4675770.html Sent from the datatable-help mailing list archive at Nabble.com.