Abstract.We develop the analysis of stabilized sparse tensor-product finite element methods for high-dimensional, non-self-adjoint and possibly degenerate second-order partial differential equations of the form −a :where a ∈ R d×d is a symmetric positive semidefinite matrix, using piecewise polynomials of degree p ≥ 1. Our convergence analysis is based on new high-dimensional approximation results in sparse tensor-product spaces. We show that the error between the analytical solution u and its stabilized sparse finite element approximation u h on a partition of Ω of mesh size h = hL = 2 −L satisfies the following bound in the streamline-diffusion norm ||| · |||SD, provided u belongs to the space H k+1 (Ω) of functions with square-integrable mixed (k + 1)st derivatives: Mathematics Subject Classification. 65N30. Received March 7, 2007. Received February 11, 2008. Published online July 30, 2008 Dedicated to Henryk Woźniakowski, on the occasion of his 60th birthday.