<p>A single-index regression model is considered, from which a robust and efficient inference about the model parameters is proposed. From a local linear approximation of the unknown regression function, such a function is estimated using the generalized signed-rank approach. Next considering the estimated function together with the estimating equation obtained from the generalized sign-rank objective function, a penalized empirical likelihood objective function of the index parameter is defined, from which its asymptotic distribution is established under mild regularity conditions. The performance of the proposed method is demonstrated via extensive Monte Carlo simulation experiments. The obtained simulation results are compared with those obtained from a normal approximation alternative and those obtained based on the least squares and least absolute deviations approaches. Finally, a real data example is given to illustrate the proposed methodology.</p>