A Multi-Level-Algorithm for the Solution of Second Order Elliptic Differential Equations on Sparse Grids Christoph Pflaum Institut f"ur Informatik, Technische Universit"at M"unchen D-80290 M"unchen, Germany e-mail: pflaum@informatik.tu-muenchen.de A multilevel algorithm is presented that solves general second order elliptic partial differential equations on adaptive sparse grids. The multilevel algorithm consists of several V-cycles. Suitable discretizations provide that the discrete equation system can be solved in an efficient way. Numerical experiments show a convergence rate of order $O(1)$ for the multilevel algorithm.