diff --git a/forms/UploadField.php b/forms/UploadField.php
index e117f357e..cc400107a 100644
--- a/forms/UploadField.php
+++ b/forms/UploadField.php
@@ -282,7 +282,8 @@ class UploadField extends FileField {
 			'UploadFieldThumbnailURL' => $this->getThumbnailURLForFile($file),
 			'UploadFieldRemoveLink' => $this->getItemHandler($file->ID)->RemoveLink(),
 			'UploadFieldDeleteLink' => $this->getItemHandler($file->ID)->DeleteLink(),
-			'UploadFieldEditLink' => $this->getItemHandler($file->ID)->EditLink()
+			'UploadFieldEditLink' => $this->getItemHandler($file->ID)->EditLink(),
+			'UploadField' => $this
 		));
 		// we do this in a second customise to have the access to the previous customisations
 		return $file->customise(array(
@@ -602,11 +603,15 @@ class UploadField extends FileField {
 	 * @param File
 	 */
 	protected function attachFile($file) {
+		$replaceFileID = $this->getRequest()->requestVar('ReplaceFileID');
 		$record = $this->getRecord();
 		$name = $this->getName();
 		if ($record && $record->exists()) {
-			if ($record->has_many($name) || $record->many_many($name)) {
+			if (($record->has_many($name) || $record->many_many($name))) {
 				if(!$record->isInDB()) $record->write();
+				if ($replaceFileID){
+					$record->{$name}()->removebyId($replaceFileID);
+				}				
 				$record->{$name}()->add($file);
 			} elseif($record->has_one($name)) {
 				$record->{$name . 'ID'} = $file->ID;
@@ -988,6 +993,8 @@ class UploadField_SelectHandler extends RequestHandler {
 		// Generate the folder selection field.
 		$folderField = new TreeDropdownField('ParentID', _t('HtmlEditorField.FOLDER', 'Folder'), 'Folder');
 		$folderField->setValue($folderID);
+		
+		
 
 		// Generate the file list field.
 		$config = GridFieldConfig::create();
@@ -1016,6 +1023,11 @@ class UploadField_SelectHandler extends RequestHandler {
 			$folderField,
 			$fileField
 		);
+		
+		//Existing file to replace
+		if ($replaceFileID = $this->parent->getRequest()->requestVar('ReplaceFileID')) {
+			$selectComposite->push(new HiddenField('ReplaceFileID','ReplaceFileID', $replaceFileID));
+		}
 
 		return $selectComposite;
 	}
diff --git a/javascript/UploadField.js b/javascript/UploadField.js
index f5f02edd0..364890374 100644
--- a/javascript/UploadField.js
+++ b/javascript/UploadField.js
@@ -169,13 +169,21 @@
 			onunmatch: function() {
 				this._super();
 			},
-			openSelectDialog: function() {
+			openSelectDialog: function(uploadedFile) {
 				// Create dialog and load iframe
 				var self = this, config = this.getConfig(), dialogId = 'ss-uploadfield-dialog-' + this.attr('id'), dialog = jQuery('#' + dialogId);
 				if(!dialog.length) dialog = jQuery('<div class="ss-uploadfield-dialog" id="' + dialogId + '" />');
-
+				
+				// If user selected 'Choose another file', we need the ID of the file to replace
+				var iframeUrl = config['urlSelectDialog'];
+				var uploadedFileId = null;
+				if (uploadedFile && uploadedFile.attr('data-fileid') > 0){
+					uploadedFileId = uploadedFile.attr('data-fileid');
+					iframeUrl = iframeUrl + '?ReplaceFileID=' + uploadedFileId;
+				}
+				
 				// Show dialog
-				dialog.ssdialog({iframeUrl: config['urlSelectDialog'], height: 550});
+				dialog.ssdialog({iframeUrl: iframeUrl, height: 550});
 
 				// TODO Allow single-select
 				dialog.find('iframe').bind('load', function(e) {
@@ -191,7 +199,7 @@
 					contents.find('input[name=action_doAttach]').unbind('click.openSelectDialog').bind('click.openSelectDialog', function() {
 						// TODO Fix entwine method calls across iframe/document boundaries
 						var ids = $.map(gridField.find('.ss-gridfield-item.ui-selected'), function(el) {return $(el).data('id');});
-						if(ids && ids.length) self.attachFiles(ids);
+						if(ids && ids.length) self.attachFiles(ids, uploadedFileId);
 
 						dialog.ssdialog('close');
 						return false;
@@ -199,14 +207,18 @@
 				});
 				dialog.ssdialog('open');
 			},
-			attachFiles: function(ids) {
+			attachFiles: function(ids, uploadedFileId) {
 				var self = this, config = this.getConfig();
 				$.post(
 					config['urlAttach'], 
-					{'ids': ids},
+					{'ids': ids, 'ReplaceFileID': uploadedFileId},
 					function(data, status, xhr) {
 						var fn = self.fileupload('option', 'downloadTemplate');
-						self.find('.ss-uploadfield-files').append(fn({
+						var container = self.find('.ss-uploadfield-files');
+						if (config['allowedMaxFileNumber'] == 1){
+							container.empty();
+						}
+						container.append(fn({
 							files: data,
 							formatFileSize: function (bytes) {
 								if (typeof bytes !== 'number') return '';
@@ -403,7 +415,7 @@
 		$('div.ss-upload .ss-uploadfield-fromfiles').entwine({
 			onclick: function(e) {
 				e.preventDefault();
-				this.getUploadField().openSelectDialog();
+				this.getUploadField().openSelectDialog(this.closest('.ss-uploadfield-item'));
 			}
 		});
 	});
diff --git a/templates/Includes/UploadField_FileButtons.ss b/templates/Includes/UploadField_FileButtons.ss
index 6fbb0e185..c8380f91f 100644
--- a/templates/Includes/UploadField_FileButtons.ss
+++ b/templates/Includes/UploadField_FileButtons.ss
@@ -13,4 +13,8 @@
 <% if canDelete %>
 	<button data-href="$UploadFieldDeleteLink" class="ss-uploadfield-item-delete ss-ui-button ui-corner-all" title="<% _t('UploadField.DELETEINFO', 'Permanently delete this file from the file store') %>" data-icon="minus-circle"><% _t('UploadField.DELETE', 'Delete from files') %></button>
 <% end_if %>
+<% if UploadFieldHasRelation && UploadField.canAttachExisting %>
+	<button class="ss-uploadfield-item-choose-another ss-uploadfield-fromfiles ss-ui-button ui-corner-all" title="<% _t('UploadField.CHOOSEANOTHERINFO', 'Replace this file with another one from the file store') %>" data-icon="network-cloud">
+	<% _t('UploadField.CHOOSEANOTHERFILE', 'Choose another file') %></button>
+<% end_if %>