diff --git a/Classes/PHPExcel/Writer/CSV.php b/Classes/PHPExcel/Writer/CSV.php
index cd536fb..17daf67 100644
--- a/Classes/PHPExcel/Writer/CSV.php
+++ b/Classes/PHPExcel/Writer/CSV.php
@@ -118,12 +118,16 @@ class PHPExcel_Writer_CSV implements PHPExcel_Writer_IWriter {
 			fwrite($fileHandle, "\xEF\xBB\xBF");
 		}
 
-		// Convert sheet to array
-		$cellsArray = $sheet->toArray('', $this->_preCalculateFormulas);
+		//	Identify the range that we need to extract from the worksheet
+		$maxCol = $sheet->getHighestColumn();
+		$maxRow = $sheet->getHighestRow();
 
 		// Write rows to file
-		foreach ($cellsArray as $row) {
-			$this->_writeLine($fileHandle, $row);
+		for($row = 1; $row <= $maxRow; ++$row) {
+			// Convert the row to an array...
+			$cellsArray = $sheet->rangeToArray('A'.$row.':'.$maxCol.$row,'', $this->_preCalculateFormulas);
+			// ... and write to the file
+			$this->_writeLine($fileHandle, $cellsArray[0]);
 		}
 
 		// Close file
diff --git a/changelog.txt b/changelog.txt
index 75185b7..d48f107 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -26,6 +26,7 @@
 Fixed in SVN:
 - General:  (MBaker) Fix to build to ensure that Examples are included with the documentation
 - General:  (MBaker) Reduce cell caching overhead using dirty flag to ensure that cells are only rewritten to the cache if they have actually been changed
+- General:  (MBaker) Improved memory usage in CSV Writer
 - Bugfix:   (MBaker) Work item 15459 - Invalid cell coordinate in Autofilter for Excel2007 Writer
 - Bugfix:   (MBaker) Work item 15518 - PCLZip library issue
 - Bugfix:   (MBaker) Work item 15537 - Excel2007 Reader canRead function bug