The purpose of this study was to evaluate the tissue penetration insertion force of different dilator tip geometries in simulated tissue. Four different dilator tip designs - conical (control), triangular, diamond, and biconvex - were appraised. The penetration force for each dilator was measured by using an ad hoc device. Each modified dilator required significantly less force necessary for "tissue" insertion compared with the conical control (P <.05 for all designs). These data suggest that angled dilator tips may facilitate insertion and may contribute to new dilator and catheter tip design.