This article considers exponential tracking with disturbance attenuation by output feedback (ETDAOF) control for systems with time delay in the process input. It is shown that the stability of such systems can be analyzed through a small-gain theorem. This robust stability analysis method is helpful in making decisions in controller synthesis. The analysis method is used to synthesize an ETDAOF controller for a highly nonlinear pH neutralization process. Simulation results are presented.