In response to an article by de Gruijter and Hambleton (1984), some thoughts on the use of decision theory for setting cutoff scores on mastery tests are presented. This paper argues that decision theory offers much more than suggested by de Gruijter and Hambleton and that an attempt at evaluating its potentials for mastery testing should address the full scale of possibilities. As for the problems de Gruijter and Hambleton have raised, some of them disappear if proper choices from decision theory are made, while others are inherent in mastery testing and will be encountered by any method of setting cutoff scores. Further, this paper points at the development of new technology to assist the mastery tester in the application of decision theory. From this an optimistic attitude towards the potentials of decision theory for mastery testing is concluded.