Finite-differences methods such as the Lax-Wendroff method (LW) are commonly used to solve 1D models of blood flow. These models solve for blood flow and lumen area and are useful in disease research, such as hypertension and atherosclerosis, where flow and pressure are good indicators for the presence of disease. Despite the popularity of the LW method to solve the blood flow equations, no implementation of a LW solver for these equations has been published and made publicly available. This leads to the reimplementation of the same methods within different research groups and makes verification of results more difficult. The Vascular Modelling in Python (VaMpy) toolkit is a Python package that aims to fill this gap. It implements Richtmyer’s two-step Lax-Wendroff scheme to solve 1D model equations of blood flow in arterial trees and aims at facilitating the solution of blood flow problems for various medical applications.