In medical technology assessment, randomized control trials (RCTs) play an important role in determining the relative efficacy of compared treatments. As scarce resources necessitate choosing among options for care, comparing costs of alternative tests, treatments, or programs also becomes important. This study assessed the prevalence and completeness of economic analyses in RCTs published from January 1966 through June 1988. It was found that only 121 of over 50,000 published randomized trials (0.2%) included economic analyses. For a random sample of 51 of these 121 studies, results revealed a mean quality of research score of 0.32 (SD of measurement = 0.14) and a mean economic analysis completeness score of 0.52 (SD = 0.13) on scales of 0 to 1. It was also found that higher economic completeness scores were positively correlated with later dates of publication (r = 0.28, P = 0.046) and with the presence of a statement of study perspective (r = 0.38, P = 0.006). A near-zero correlation between the economic completeness and the quality of research scores was revealed. Also noted were several deficiencies among the economic analyses, including improper allocation of overhead costs, absence of sensitivity analyses, and the fact that only 28% of the 51 studies included some form of aggregation of treatment costs and consequences. Progress in health care depends on accurate assessments of both relative efficacy and costs. The quality of both needs improvement.