This paper considers the numerical solution of boundary integral equations of the sec-rnond kind, for Laplace's equation _u = 0 on connected regions in R3 with bound-rnary @. The boundary @ is allowed to be smooth or piecewise smooth; and we letrnf4kj1 _ k _ ng be a triangulation of @. The paper will focus on the derivation ofrnthe boundary integral equation (BIE) for the Laplace equation, and numerical resultsrnare presented for some examples using constant elements.