Bone fractures are common in human beings, and the surgical operation performed to repair the fractured bone includes the drilling process. Axial cutting force during drilling plays an important role for success in osteosynthesis. Many processes like water jet machining, laser drilling, ultrasonic drilling, two phase drilling and rotary ultrasonic bone drilling (RUBD), have been developed to minimize the cutting force during orthopedic drilling. In the present work, a novel operation theatre compatible ultrasonic assisted rotary bone drilling machine prototype have been designed and fabricated in an attempt to reduce the cutting forces produced during orthopedic drilling. The experimental test were performed on fresh porcine bone and human femur. A comparative study was carried out between RUBD and Conventional drilling (CD), to find out the influence of rotational speed, drilling tool feed rate and drill diameter, on the cutting force produced during the drilling. The study of chip produced in RUBD and CD was also carried out with the help of scanning electron microscopy images. The result obtained by the developed machine showed that the cutting force obtained in human femur was greater (20–25 %) than porcine femur due to its greater hardness and RUBD process produced lower cutting force (20–30 %) than CD for both types of bone. The experimental results showed the increase in cutting force with decreasing rotational speed and increasing feed rate and drill diameter.