Electronic Journal of Differential Equations, Vol. 2003(2003), No. 42, pp. 1-10. Title: A discontinuous problem involving the p-Laplacian operator and critical exponent in $\mathbb{R}^N$ Authors: Claudianor Oliveira Alves (Univ. Federal de Campina Grande, Brazil) Ana Maria Bertone (Univ. Federal da Paraiba, Brazil) Abstract: Using convex analysis, we establish the existence of at least two nonnegative solutions for the quasilinear problem $$ -\Delta_{p}u=H(u-a)u^{p^*-1} +\lambda h(x)\quad\hbox{in }\mathbb{R}^N $$ where $\Delta_{p}u$ is the $p$-Laplacian operator, $H$ is the Heaviside function, $p^*$ is the Sobolev critical exponent, and $h$ is a positive function. Submitted September 23, 2002. Published April 16, 2003. Math Subject Classifications: 35A15, 35J60, 35H30. Key Words: Variational methods; discontinuous nonlinearities; critical exponents.