Drug samples are often packaged differently from bulk packaging and thus they may contain a disproportionate amount of waste material. Fifteen drug samples were obtained from seven pharmaceutical companies and the packaging materials were weighed after the samples were removed. The waste produced by the samples was determined for a standard amount of drug and compared with the weight of the waste produced when the same quantity of drug was dispensed through a pharmacy. The average weight of the sample package for a standard course of therapy was significantly greater (p< or =0.05) than that of the pharmacy-dispensed prescription waste weight. The former was 5+/-4.5-fold heavier than the latter. The waste generated by drug samples in the United States was determined to be 5740 metric tons/year.