This paper presents a new design of longitudinal and torsional (L&T) ultrasonic vibration device for accurate needle insertion in medical applications. A waveguide-based Langevin type L&T ultrasonic transducer is proposed for the vibration-assisted insertion device. By cyclically altering the amplitude and direction of the resultant insertion speed, the proposed three-dimensional L&T ultrasonic vibration superimposed on the needle can reduce the friction force and needle bending during the insertion. Analytical modeling and analysis were conducted to study the vibration characteristics of the design. The new L&T ultrasonic transducer was fabricated using a metal 3D printing process. Laboratory experiments were carried out to validate the effectiveness of the new L&T vibration transducer design. The experiment results show the proposed new L&T vibratory needle insertion device is able to accurately deliver the insertion needle to the target depth and location. The presented new design and techniques can be used for medical treatments and implantation applications.