In this post we’ll see how to merge the two or more cell with each other while creating the excel sheet using NPOI . Mentioned below is code to merge multiple cells, in this example we are merging first cell to fifth cell of first row (you can adjust row or cell range by passing particular parameters in CellRangeAddress). //Created new Workbook var hwb = new NPOI.HSSF.UserModel. HSSFWorkbook (); //Create worksheet with name. var sheet = hwb.CreateSheet( "new sheet" ); //Create row and cell. var row = sheet.CreateRow(0); var cell = row.CreateCell(0); ; //Set text inside cell cell.SetCellValue( "This is Merged cell" ); cell.CellStyle.WrapText = true ; //define cell range address // parameters: -> first row to last and first cell to last cell var cra = new NPOI.SS.Util. CellRangeAddress (0, 0, 0, 4); //Add merged region to sheet. sheet.AddMergedRegion(cra); Hope this solution helps you J