I've submitted a ticket #570 that includes an updated version of slsqp.py. The function fmin_slsqp should now properly accept constraints via the callable arguments f_eqcons and f_ieqcons. In addition, callable arguments that provide the constraint jacobians are also working now. I also added a function to slsqp.py for approximating the Jacobians if fprime_eqcons or fprime_ieqcons are not provided. Perhaps this routine would be better off in scipy.common, since its very similar to approx_fprime. I also attached a new version of slsqp_test.py to the ticket that now shows examples of how to use fmin_slsqp with the new constraint arguments. Please let me know if you have any questions or uncover any more issues. http://scipy.org/scipy/scipy/ticket/570 - Rob Falck