This paper describes some of the issues that must be addressed in the use of Computational Aeroacoustics (CAA) for the solution of problems of practical importance. Solutions to some of these difficulties are also given. Previous studies have only emphasized the development of algorithms and their application to relatively simple model problems. The particular issues addressed in this paper include: the computational resources required for CAA calculations; grid selection; boundary treatments; equation and algorithm selection; artificial dissipation; Kirchhoff methods; and, post-processing. Examples of computational aeroacoustic calculations are given for ducted fans and jets. The need for three-dimensional, non-linear simulations and the feasibility of such solutions on high performance parallel computers is emphasized.