Purpose -To determine what criteria are used in enterprise resource planning (ERP) selection process and what criteria are the most important for firms. Design/methodology/approach -Through an extensive literature review, 15 selection criteria for the ERP selection process were identified and two were added after initial interviews. A questionnaire including these criteria was formed to secure data from companies. A single informant method was used for each company. To measure the importance of various critical factors a five-point Likert scale was used in the questionnaire. Findings -Fit with parent/allied organisation systems is identified as the most important selection criterion. Cross-module integration, compatibility between other systems, and references of the vendor are identified important factors respectively. Statistically significant differences were also determined between companies using MRP/MRPII versus those using own or no program for "better fit with organisational structure" and "fit with parent/allied organisational systems" criteria.Research limitations/implications -The effect of each selection criterion on ERP implementations failure rates is still to be investigated. Practical implications -Useful information about selection criteria on ERP systems for both vendors and firms planning to use these systems. Originality/value -Two new selection criteria were proposed for the ERP system selection process and some important differences between the criteria used by firms from developed countries and developing countries are determined.