diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -1888,6 +1888,27 @@
 Convert angle x from degrees to radians.");
 
 static PyObject *
+math_isclose(PyObject *self, PyObject *args, PyObject *kw)
+{
+    double x, y, rel_tol = 1e-9, abs_tol = 0.0;
+    double absx, absy, tol;
+    static char *keywords[] = {"x", "y", "rel_tol", "abs_tol"};
+    if (!PyArg_ParseTupleAndKeywords(args, kw, "dd|dd:isclose", keywords, 
+				     &x, &y, &rel_tol, &abs_tol))
+        return NULL;
+    absx = fabs(x);
+    absy = fabs(y);
+    tol = rel_tol * ((absx > absy)?absx:absy);
+    if (abs_tol > tol)
+	tol = abs_tol;
+    return PyBool_FromLong(fabs(x - y) <= tol);
+}
+
+PyDoc_STRVAR(math_isclose_doc,
+"isclose(x, y, rel_tol=1e-9, abs_tol=0.0) -> bool\n\n\
+Return True if if x is close in value to y. False otherwise.");
+
+static PyObject *
 math_isfinite(PyObject *self, PyObject *arg)
 {
     double x = PyFloat_AsDouble(arg);
@@ -1951,6 +1972,8 @@
     {"fsum",            math_fsum,      METH_O,         math_fsum_doc},
     {"gamma",           math_gamma,     METH_O,         math_gamma_doc},
     {"hypot",           math_hypot,     METH_VARARGS,   math_hypot_doc},
+    {"isclose",         (PyCFunction)math_isclose,
+                          METH_VARARGS|METH_KEYWORDS,   math_isclose_doc},
     {"isfinite",        math_isfinite,  METH_O,         math_isfinite_doc},
     {"isinf",           math_isinf,     METH_O,         math_isinf_doc},
     {"isnan",           math_isnan,     METH_O,         math_isnan_doc},