A sleeve monopole is a conventional monopole antenna surrounded by a grounded metal tube (the sleeve). A relatively simple numeri-cal method is presented for obtaining a Fourier series representation of the current on both the monopole and its sleeve. The impedance and radiation pattern are also found. No limitation is placed on the radius of the sleeve. A special case of the numerical procedure yields the current, impedance, and pattern for an ordinary (sleeveless) monopole driven at any point along its length. Theoretical results derived here for the sleeve monopole agree well with published experimental data.