--- a/scripts/polynomial/polygcd.m
+++ b/scripts/polynomial/polygcd.m
@@ -81,3 +81,24 @@
   endif
 
 endfunction
+
+
+%!test
+%! poly1 = [1 6 11 6]; % (x+1)(x+2)(x+3)
+%! poly2 = [1 3 2]; % (x+1)(x+2)
+%! poly3 = polygcd (poly1, poly2);
+%! assert (poly3, poly2, sqrt (eps))
+
+%!test
+%! assert (polygcd (poly(1:8), poly(3:12)), poly(3:8), sqrt (eps))
+
+%!test
+%! assert (deconv (poly(1:8), polygcd (poly(1:8), poly(3:12))), poly(1:2), sqrt (eps))
+
+%!test 
+%! for ii=1:10
+%!   p  = (unique (randn (10, 1)) * 10).';
+%!   p1 = p(3:end);
+%!   p2 = p(1:end-2);
+%!   assert (polygcd (poly (-p1), poly (-p2)), poly (- intersect (p1, p2)), sqrt (eps))
+%! endfor