A computerized bank of azeotropic data is now available. Data from the literature have been tested before storage. Newly measured azeotropic and zeotropic data are also included, which were obtained for the purpose of verifying questionable literature information and also for systems for which no data had been available. This data bank now contains approximately 36 000 entries (information) on azeotropic or zeotropic behavior or approximately 19 000 non-electrolyte systems involving approximately 1700 compounds. It can be used reliably in process synthesis computations, e.g. for design calculations of distillation columns, selection of the best solvents for azeotropic distillation and also for further development of group contribution methods or for fitting reliable g(E)-model parameters. This compilation will increase the capabilities of existing software tools, such as the Dortmund Data Bank and the integrated program packages (Gmehling, J., 1991. Development of thermodynamic models with a view to the synthesis and design of separation processes. In : J. Gmehling (Ed.), Software Development in Chemistry 5. Springer-Verlag, Berlin, Chapter 1.) for process design, synthesis and simulation.