Most of the trocars provided with systems for suprapublic puncture are not entirely acceptable due to inadequate technical development. Since suprapublic trocars are particularly useful in clinical practice, we developed a new type of trocar with several improvements. The tip of the new trocar has three functional parts. The first third is a hard very sharp lancet which perforates the tissue layers like a scalpel. The second third of the tip is more flexible and cuts a half-circle. The last third has a smooth edge which separates and dilates the borders of the opening. This eliminates the punch effect and ensures a constant contact between the body of the trocar and the catheter placed within its central groove. The trocar has a continuous curve between its dilating part and the body for smooth insertion. Entry is controlled with a handle, thus avoiding accidental lesions. Since the tissues are elastic, the wound closes spontaneously when the trocar is removed. The advantages of the new puncture system have been confirmed with clinical data.