The Zero-Effort-Miss/Zero-Effort-Velocity (ZEM/ZEV) with sliding mode guidance scheme is applied to the problem of asteroid proximity-operations orbit transfer and rendezvous. This guidance scheme is a non-linear methodology which combines techniques from both optimal and sliding control theories to generate a guidance framework which generates a thrust command based purely on the current estimated spacecraft state and desired final target state. The guidance algorithm has its roots in the generalized ZEM/ZEV feedback guidance and its mathematical equations are naturally derived by defining a non-linear sliding surface as a function of the terms Zero-Effort-Miss and Zero-Effort-Velocity. With the addition of this sliding mode augmentation, one can formally prove that the developed guidance law is globally stable to unknown, but bounded perturbations. In this paper, the focus is the application of the guidance law to typical scenarios that can be encountered during the closeproximity operations phases of a robotic mission to a small asteroid. First, the problem of orbit transfer is analyzed and simulations are executed to determine the performance in such a scenario. Secondly, the problem of orbital rendezvous is assessed and analyzed and the performance of the guidance is again discussed. Results demonstrate that the algorithm performs well even in a largely uncertain environment and features high accuracy in the execution of such maneuvers.