Several thousand distinct medical devices exist and for each one the user usually has a choice from among a number of manufacturers. The process whereby a clinician or hospital purchasing agent makes a selection from a number of competing brands may be based on anything from, on the one extreme, little more than an emotional attraction to a particular brand name to, at the other end of the spectrum, a fully enlightened choice after an inhouse evaluation together with extensive additional information. This paper will describe, with concrete examples drawn from the ensemble of equipment used in the fields of resuscitation and critical care, how Emergency Care Research Institute evaluates such devices, investigates hazards associated with these instruments, and communicates this information to users.