diff --git a/docs/source/api.rst b/docs/source/api.rst
index 7c6fd70a..6c6c5c1b 100644
--- a/docs/source/api.rst
+++ b/docs/source/api.rst
@@ -38,6 +38,8 @@ The :meth:`~sqlparse.format` function accepts the following keyword arguments.
 ``truncate_strings``
   If ``truncate_strings`` is a positive integer, string literals longer than
   the given value will be truncated.
+  Truncation does not split doubled quotes or backslash escape sequences;
+  the retained content may be shorter than the requested width.
 
 ``truncate_char`` (default: "[...]")
   If long string literals are truncated (see above) this value will be append
diff --git a/sqlparse/filters/tokens.py b/sqlparse/filters/tokens.py
index cc00a844..395ca4a4 100644
--- a/sqlparse/filters/tokens.py
+++ b/sqlparse/filters/tokens.py
@@ -5,6 +5,8 @@
 # This module is part of python-sqlparse and is released under
 # the BSD License: https://opensource.org/licenses/BSD-3-Clause
 
+import re
+
 from sqlparse import tokens as T
 
 
@@ -47,13 +49,14 @@ def process(self, stream):
                 yield ttype, value
                 continue
 
-            if value[:2] == "''":
-                inner = value[2:-2]
-                quote = "''"
-            else:
-                inner = value[1:-1]
-                quote = "'"
-
+            inner = value[1:-1]
             if len(inner) > self.width:
-                value = ''.join((quote, inner[:self.width], self.char, quote))
+                # Keep doubled quotes and backslash escapes intact at the
+                # truncation boundary, without exceeding the requested width.
+                end = 0
+                for match in re.finditer(r"''|\\.|.", inner, re.DOTALL):
+                    if match.end() > self.width:
+                        break
+                    end = match.end()
+                value = ''.join(("'", inner[:end], self.char, "'"))
             yield ttype, value
diff --git a/tests/test_format.py b/tests/test_format.py
index 93495067..27d6221f 100644
--- a/tests/test_format.py
+++ b/tests/test_format.py
@@ -738,6 +738,27 @@ def test_truncate_strings():
     assert formatted == "update foo set value = 'xxxYYY';"
 
 
+@pytest.mark.parametrize('marker', ['[...]', '...', ''])
+@pytest.mark.parametrize(('literal', 'width', 'expected'), [
+    ("'ab''cdef'", 3, "'ab[...]'"),
+    ("'ab''cdef'", 4, "'ab''[...]'"),
+    ("'''abcdef'", 3, "'''a[...]'"),
+    ("'''abcdef'", 6, "'''abcd[...]'"),
+    ("'a\nb''cdef'", 4, "'a\nb[...]'"),
+    ("'ab''''cdef'", 5, "'ab''[...]'"),
+    ("'ab''''cdef'", 6, "'ab''''[...]'"),
+    (r"'ab\'cdef'", 3, "'ab[...]'"),
+    (r"'ab\'cdef'", 4, r"'ab\'[...]'"),
+    (r"'ab\\cdef'", 3, "'ab[...]'"),
+    (r"'ab\\cdef'", 4, r"'ab\\[...]'"),
+    ("'ab''cd'", 6, "'ab''cd'"),
+])
+def test_truncate_strings_preserves_escapes(literal, width, expected, marker):
+    formatted = sqlparse.format(f'SELECT {literal};', truncate_strings=width,
+                               truncate_char=marker)
+    assert formatted == 'SELECT {};'.format(expected.replace('[...]', marker))
+
+
 @pytest.mark.parametrize('option', ['bar', -1, 0])
 def test_truncate_strings_invalid_option2(option):
     with pytest.raises(SQLParseError):