The most-probable number (MPN) method is frequently used for counting microorganisms. It can provide accurate numbers if an adequate experimental design is planned. However, the major inconvenience limiting its use is the lack of tables covering any possible MPN design. This report presents a simple, flexible, general purpose program that constructs MPN tables for any desired number of levels or dilutions, tubes per level, dilution factor, and volume of inoculated sample. Thus, this program can make the MPN technique available for more general use.