We present theoretical results for the electrical conductance G of a quantum dot in the presence of superconductivity. After deriving a generalization of the well-known Breit-Wigner formula, valid in the presence of superconducting leads, results for the distribution of conductance resonances are derived. For a normal (N) contact-normal dot (NDOT)-superconducting (S) contact, as the order parameter Δ of the S contact tends to zero, recent predictions for the resonant structure of a normal chaotic dot are reproduced. When Δ increases from zero, for finite applied voltage, resonances are destroyed.