Use following Code
StreamReader sr = new StreamReader(@"d:simpleTabDelimeterFile.txt"); StreamWriter outputFile = new StreamWriter(@"d:out.txt"); string strline = ""; string[] _values = null; while (!sr.EndOfStream) { strline = sr.ReadLine(); _values = strline.Split('t'); if( _values.Length == 3 ) { strline = _values[0] + 't' + _values[1] + 't' + _values[2]; outputFile.WriteLine(strline); } } sr.Close(); outputFile.Close();