Lorenz and concentration curves are widely used tools in inequality research. In this article, I present a new command, lorenz, that estimates Lorenz and concentration curves from individual-level data and, optionally, displays the results in a graph. The lorenz command supports relative, generalized, absolute, unnormalized, custom-normalized Lorenz, and concentration curves. It also provides tools for computing contrasts between different subpopulations or outcome variables. lorenz fully supports variance estimation for complex samples.