Polymer matrix composites (PMC’s) are versatile class of materials used in several industries like automobile, aerospace, sports and medical to fabricate different components owing to their outstanding mechanical characteristics, impressive strength to weight ratio and superior resistance to corrosion. However, the assembling of these components can be ensured through the fastening methods accompanied through the holes drilled in PMC’s. Several machining methods have been employed to drill holes in PMC’s such as conventional drilling, ultrasonic machining,, laser beam processing and high pressure abrasive jet cutting. Among all these methods, ultrasonic machining process exhibit several advantages over other processes due to its low operational cost, easy to use and compact setup. In recent years, ultrasonic machining (USM) process has been used extensively through different variations to drill holes in natural, glass and carbon fiber polymer composites. This paper presents an overview of all these process variations of ultrasonic machining used to drill holes in PMC’s. The influences of process parameters such as power rating, amplitude of vibrations, tool rotation speed and frequency of vibrations on drilled hole quality is also included. The process and material removal mechanisms have been discussed in perspective of different fiber materials. The challenges with respect to all process variations are also included, and their respective feasible solutions are proposed as future opportunities.