A new method for measuring political clientelism is developed: the Systematic Qualitative Method (SQM). Ideal for measuring clientelism, the new method is also easily adapted to measure other kinds of social phenomena for which there is no available data. After elaborating a detailed guide for using the method, its validity is established by comparing SQM measurement of clientelism in Argentina and Brazil with existing measures found in the literature. Finally, the results of SQM measurement of clientelism in Argentina and Brazil are presented. An analysis of variation in clientelism within and across the two countries yields some hypotheses for future research.